Table of Contents

Production Team

Production Team

Contributing Authors

Editorial

DATV News

Normal service restored

Friedrichshafen

ZERO ROBOTICS

AMSAT-UK Colloquium

Happy anniversary

Silent key

50 Years of Colour Television

Amateur Television Quarterly

Results IARU ATV activity weekend/contest 2017

Highlights:

70 cm

23 cm

13 cm

9 cm

6 cm

3 cm

1.2 cm

Totals

Micro Corner - Node MCU BASIC and I2C control

Node MCU Module and pin out

Some entertaining and useful links

TV Amateur

A Digital World - An Introduction to DATV

Building the Portsdown in the real world

The morals of this tale

Gave a good Digital-ATV Presentation to JPL Ham Club in Pasadena

MORSE CODE LIVES ON MARS

MISSION CONTRL CENTER

Contact Info

MP3 Sound Module Review & Application Notes

Module Hardware

Uploading your own audio clips

Control Methods

Ardunio Test Code

ESP8266 Test Code

Serial commands – Hexadecimal Format

Conclusion

A Simple Home Constructes Weather Station

DKARS advert

GB3FT - A 24cm Digital ATV Repeater for the Fylde Coast

Background history

GB3FT Status and Coverage

GB3FT Hardware

Transmitter Section

Receiver and Command Section

Conclusion

DATV-Express Project - June update report

The popular Video sync generator; The new ‘Syncsmurf’!

Introduction

Syncsmurf2

Technical data

Documentation for the builders

Placement hard to read parts:

Interested?

Warning

DATV Express advert

Information

About this eBook

External links

Legal Niceties (the small print)

Copyright

Notice to Contributors

Coming up

CQ-DATV 50 Credits

Production Team

- Terry Mowles - VK5TM

- Ian Pawson - G8IQU

- Trevor Brown - G8CJS

Contributing Authors

- Trevor Brown - G8CJS

- John Hudson - G3RFL

- Ken Konechy - W6HHC

- Bob Dyer - G1XIE

- Tim Forrester - G4WIM

- David PE1MUD and Tjalling PE1RQM

- Chris van den Berg - PA3CRX

- Richard Carden - VK4XRL

- Mike Stevens - G7GTN

Please note: articles in this magazine are provided with absolutely no warranty whatsoever; neither the contributors nor CQ-DATV accept any responsibility or liability for loss or damage resulting from readers choosing to apply this content to theirs or others computers and equipment.

Editorial

Welcome to CQ-DATV issue 50. It does seem we have reached a milestone and did not the time fly. It was a brave move to set up a free ATV publication and it could have only been done by making it an electronic only magazine. There was some logic in that we needed a publication that was going to be worldwide because, even 50 issues back, copy was starting to decline. Most of the technical authors that have contributed to previous magazines now have their own websites to publish their designs and yes, this works, but it detracts from a single focus and an audience reading a single publication over perhaps the same time frame that we hope stimulates discussion rather than numerous distributed websites with arbitrary updates.

Secondly an electronic magazine can exploit HTTP links. They are less useful if they have to be copied into a browser address bar. Now we have launched Micro Corner and the cut and paste of text can be exploited for a quick movement of a programme from screen to micro. So it would seem to have more advantages than disadvantages, particularly if you remember BASIC programmes back in the BBC home computer and Spectrum computer days and the hours spent copy typing programmes from paper magazines.

Why is it so important to reach worldwide audience? Well, the original concept was to write a few magazines, publish and people would download, read and the contributions would roll in so we could just select and print the ones we thought publication worthy. So we were effectively running a newspaper without journalists or feature writers. This failed and the CQ-DATV 49 issue was thin to the point where we wondered if there would be a CQ-DATV 50. We appealed for copy and articles emerged and we are indebted to the people who took the time and effort to contribute, Their names are published alongside their articles. The group we also call the staff writers (grand title almost makes you think they are paid a salary) also moved up a gear and so we are proud to produce CQ-DATV 50.

If we are going to continue and buck the trend that other ATV magazines are suffering, then we need to carry on this impetus. So please read CQ-DATV 50, but ask yourself 'could I contribute?' Do we have a local repeater people would like to read about, have I been anywhere that has ATV activity that I could share. It’s not all about designing a complex circuit. We know people who can do this are perhaps a dying breed, but also we know some of you are still out there and we would love your input.

In this action packed edition we have:-

- The full results of the IARU region 1 ATV contest

- John G3FRL has sorted out what started as a Maplin Weather station

- Richard VK4XRL has written another Digital World

- Bob Dyer G1XIE has reported on his experiences building the Portsdown DATV Transmitter

- Tim Forrester G4WIM has documented his DATV repeater GB3FT, Ken W6HCC has produced his June DATV-Express Project report

- David PE1MUD has come up with the ultimate blue screen remover and video sync processor

- Trevor looks back on 50 years of Colour TV broadcasting

- Micro Corner, has a back to basics look at i2c, again from Trevor.

I wonder if any of you can remember i2c the first time around as a CQ-TV project when Chris Smith and Trevor engineered a Z80 machine code driven range of i2c projects. Well it's BASIC this time again a blast from the past, but ESP 8266 BASIC is quite new. Mike G7GTN is now out of the wars and his audio module for repeater idents that we hung over form the last issue is now de-bugged and presented in this issue.

This has been a tough task for our two resident Editors Terry VK5TM without who we would have never had a PDF version of CQ-DATV and Ian G8IQU the man behind the e-book concept.

Let’s hope we can keep producing magazines like this, but to do so we need your help, so please our thanks to everyone who has contributed not only to this issue but to all the previous issues.

Now sit back and enjoy CQ-DATV 50.

CQ-DATV Production team

Contents ^

DATV News

Normal service restored

I have now repaired all of the missing files from the DATV-Express.com web site…after the big crash.

Our web host “had a huge power outage…the Web Server SAN Storage system had 3 drive failures at the same time during the power problem…”.

The missing files (now restored) were mainly:

- Windows download software releases

- User Guides

- TechTalk articles on DATV

- Open Source DATV-Express hardware files - like schematics, specs, and BOM

The entire DATV-Express Project Team is sorry for any inconvenience that this crash may have caused.

73…de Ken W6HHC

Friedrichshafen

Some pictures from the Friedrichshafen 2017 event kindly submitted by Robert Warner G1SAA.

The AGAF stand and actual printed magazines!

Uwe Krause DJ8DW and his annual video link from The Pfänder mountain in Austria

Stand of ATV Munich DB0QI with self built repeater devices shown. The repeater site had to move last year to a small town near Munich called Vierkirchen

Stand of ATV Munich DB0QI with self built repeater devices shown

Stand of AGAF e.V. with beamer screen, membership data bureau and live DATV RX from Pfaender mountain (OE). Behind the desk is Evariste, F5OEO, talking to Uwe, DJ8DW, who is hidden behind the sys-op DG3KHS of ATV repeater Cologne, DB0KO

Joerg, DF3EI, AGAF first chair, at his portable membership data bureau and HAMNET streaming station DA0TV, and latest TV-AMATEUR issues near by

ZERO ROBOTICS

Zero Robotics, led in Australia by the University of Sydney’s Faculty of Engineering and Information Technologies, is one of the world’s biggest computer programming competitions. It is a robotics programming competition which challenges participants to test their coding skills on NASA robots known as SPHERES (Synchronized, Position, Hold, Engage, and Reorient Experimental Satellites) aboard the International Space Station. Teams from high schools around the world program the SPHERES to solve challenges.

In the 2016/17 competition five Australian high schools made it through to the Zero Robotics Championship Event and programmed robots in space. We had some incredible results, with our team coming second and equal third overall!

The Australia-only preliminary competition enables Australian high school students to gain valuable experience in coding. Students also learn the mathematics and physics behind the motion of the SPHERES robot and develop strategies for successful game play within the game premise. Students need to work as a team, delegate tasks, communicate effectively and be well organised. These are valuable skills that students can apply to their schoolwork and that will be invaluable should they consider further studies beyond high school.

Zero Robotics is an international robotics programming challenge where Australian high school students have the chance to write code and complete tasks using NASA robots on board the International Space Station (ISS).

Created by MIT and the University of Sydney’s former astronaut, Professor Greg Chamitoff, the competition involves over 170 teams worldwide.

In the 2016/17 competition 200 Australian students participated.

Our thanks to the University of Sydney in allowing us to use the information.

AMSAT-UK Colloquium

The AMSAT-UK Colloquium will be held in conjunction with the RSGB Convention at the Kent Hills Conference Centre in Milton Keynes MK7 6BZ (Alternative postcode for Sat Nav: MK7 6TT) over the weekend 13/14/15 October. Our Colloquium talks will take the form of a dedicated AMSAT/Space ‘stream’. We shall also have a presence in the Special Interest Groups room, keep a look out for the AMSAT stand there, and use it as an AMSAT-UK rallying point.

Happy anniversary

AMSAT commemorated the 20th Anniversary of SSTV featuring SSTV images from the past and present, via a computer on the ISS Russian Segment, which stores images that are then transmitted to Earth using the ham radio, specifically the onboard Kenwood TM-D710 transceiver. Those receiving the images can post them at https://ariss-sstv.blogspot.com/ for viewing by the public.

Want to be notified when issues of CQ-DATV are published? Then join our mailing list.

Contents ^

Silent key

Silent key - Dave Kenward, G8AJN

Dave G8AJN collecting the Grant Dixon award in 2012 from Colin G4KLB (over the air spoof)

Sadly on July the 9th Dave Kenward G8AJN passed away. Dave was a huge motivating force in the ATV world and without him we would not have had the benefit of the DigiLite project, the start of Digital ATV, which although this had been around sometime and was originally engineered by F1CJN.

Dave designed and engineered the DigiLite PCB’s, and sorted out the programming of the USB modules, and all the other little bits and pieces that made this a home constructable project.

I first came into contact with Dave when I was re-starting the BATC shop and together we looked at the costs of stocking the full range of components for this project and the price break points on the various quantities of PCB’s. I was always weary about being attracted to large PCB runs and their attractive prices, only to be stuck as so many before me had been with stock that just never sold. Dave inspired me to take a chance and risk BATC funds on the project, and he was never more right. DigiLite was a huge success and opened the digital gateway into ATV, other DATV projects have since come along but DigiLite was and will always be the first.

In 2012 the BATC awarded Dave the prestigious Grant Dixon award for services to ATV. No one deserved it more.

Colin G4KLB accepts the award on behalf of David G8AJN

Dave was also the Technical co-ordinator for the BATG (Bournemouth Amateur Television Group) that constructed and maintained GBSQ (The Digital ATV repeater)

The ATV world was the richer for all his contributions and he will sadly be missed by us all

Trevor G8CJS

Back in 2012-13 the DigiLite project was conceived by Dave. From his introduction to the project:

My contribution to the information contained in these notes has been to produce a single pcb with all the components for the serialiser and modulator. I claim no technical acumen, I am simply your guide to the system as it exists today. I aim to explain why you are doing something in terms that an analogue ATV-er can understand.

For those interested, the eBook containing all the DigiLite articles, in a single volume, is available from the  CQ-DATV web site.

Dave was very helpful to me in the creation, proof reading and providing photographs on the various parts for this publication.

Ian G8IQU

Our thoughts are with his family.

Contents ^

50 Years of Colour Television

A personal reflection by Trevor G8CJS

Yes doesn’t time fly when you are having fun. 50 years of UK colour TV broadcasting. The BBC worked the initial cost out at between £1m and £2m per year, for four hours of television per week on BBC2, rising to 10 hours a week after 12 months. The technology was cutting edge, so the corporation decided to trial it on, BBC2, which in 1967 was run by David Attenborough, where would his sort of broadcasting be without colour, just imagine. Paradise Birds and Life on Earth, without colour, so perhaps the right person in the right place at the right time. Attenborough also took advantage of other programming that would benefit from colour, Snooker, Percy Thrower’s garden and then on July 1 1967 Wimbledon was broadcast in Colour, the first colour TV transmission in Europe, presumably the players still wore white kit, but the viewers would see green grass and before you ask Billie Jean King won the women’s singles and John Newcombe won the men’s singles.

Philips PC60 Cameras, using 3 plumbicon tubes. Famous for using two camera cables

The BBC also added to their press release that colour programmes would still be available on ordinary television sets in black and white, so they were on top of compatibility, perhaps they might want to revisit the demand side, but to be fair it is really only an equipment cost and as that is replaced periodically anyway, perhaps an accelerated replacement budget and some training were the costs involved, but if you want to sell your programmes on, then colour would be the only way to go.

For me personally I remember taking an extended lunch break from college, along with several other students to go look at a demonstration by Pye, who were running a Colour TV road show for TV engineers and were in Leeds that day. Most of the engineering speak went right over my head and seeing the engineers trying to converge the Red Green and Blue pictures on a delta gun shadow mask tube did make me wonder if I had chosen the right career, (Television Engineering), as it looked like colour was a real headache, note to self stay away from TV sets and monitors. Remember BBC2 was 625 so the TV sets were dual standard and the convergence errors showed on Black and White pictures too, so it had to be right, otherwise viewers might stay with the Black and white TV with no such problems.

Late back to college and a telling off for the extended lunch break, in truth I think the lecturer was a little envious that we had seen colour TV before him and were full of all the technical buzz words, from P.A.L through to dynamic and static convergence. There were a number of references in the afternoons lectures to black and white television, that I suspected had not been in the original lesson plan.

By the 1970’s I had my first job in a TV studio, it was an educational studio that was part of the University of Leeds. The newly appointed Chief engineer came from TWW and was a bit of a Dinosaur, and had invested black and white equipment and not left an easy door open into colour as the kit evolved. The EMI image orthicons cameras were equipped with turret lenses. The VT machines were again only black and white capable, Ampex helical scan, that only used one head so there was a band of missing picture at the bottom of the screen.

University Television VTR department 1970 Ampex 7800 machines

I think I was there about two years honing my broadcast skills, before in February 1972 I made the jump to Yorkshire Television Europe’s first purpose-built colour studios, on Kirkstall Road in Leeds. YTV started transmitting colour TV in November 1969 so it was settle down and learn colour TV engineering from the bottom, working with people who were already 2 years ahead of me on the learning curve. To be honest I was surprised I got the job which was in the engineering workshop, repairing Marconi VII Cameras and P.A.L. coders, (who was this Cox guy). We had EMI cameras (2001) but they never needed fixing, just as well the Marconi’s made up that, so could colour be so difficult? well three of everything and in the case of the cameras 4 channels, did add to the engineering requirements, but on the plus side, did it create a job vacancy for me to fill,? I will never know.

Yorkshire Television as it was before the ITV branding of today

At that point I had just two years experience in the TV broadcast industry all of it on black and white kit, and most of that was spent on VTR engineering. The new job excluded Video Tape Engineering, apparently they had a specialist department that took care of that. This changed in 12 months one of the specialist VTR engineering team left ( there were only two people on the team, they kept that one quiet at the interview ). I was successful at passing the interview for his replacement, which was a promotion too. The problem was the VTR machines were Quadruplex (4 heads but a lot more than 4 times the complexity of the B/W Ampex I started with). The machines cost about £70k each and one of the accessories was a module called CAVEC (Chroma Amplitude and Velocity Error Corrector) and this was a £7k addition to improve head banding on the picture. We had just started to buy our first house, semi detached three bedroom costing £4k, does that put it in perspective. So for the other person he worked 12 hours 7 days a fortnight and I worked the other 7 so in short I was on my own (bugger).

TR70 VTR we had 6 and they were Germanium technology which as all engineers know has a finite life time. The top row of modules was the mostly FM and video processing, the bottom row was mostly servo, but the expensive CAVEC was also in this row

Ok the steep learning curve had just got steeper, YTV had 6 VTR machines and two crews driving them hard from 8am to beyond midnight, and if one was out of service for any length of time the balloon would go up, plus they had a TR50 in an outside Broadcast van which was also the responsibility of my new two man department. This older technology frequently went wrong in all sorts of exotic locations such as the Lincoln Drill Hall (Wrestling).

Colour added a lot to the VTR engineering, which all revolved around the coded signal, none of the RGB world of the cameras and a coder at the end of the chain.

P.A.L was probably the latest of the colour TV systems

Perfection At Last we called it, as opposed to Never Twice the Same Colour or System Essentially Contradictory to the American Method.

The system we had chosen was engineered by a doctor Bruch (pronounced Brook) and was indeed the better of the systems available at the time, but it also had one or two abnormalities that lead us to believe that the good doctor was not ahead on the curve at the time. The P.A.L system used a subcarrier as did NTSC and SECAM, this was not ideal, and all three suffered patterning on the picture as a result, but for P.A.L and N.T.S.C. the patterning was proportional to colour saturation, so parts of the picture with little or no colour did not suffer (unlike SECAM). To minimise the patterning the good doctor added a subcarrier crawl on the grounds that the patterning was less objectionable if it moved up the screen, and he also removed some extra colour burst in the vertical interval, to help, steer the monitors burst locked oscillator into lock quicker at the start of each field. (Bruch Blanking). There is much debate even today that this was necessary and the belief is that he had a faulty TV when he did the R&D, so this was a necessity for his TV only.

The bottom line was he thought the subcarrier to line lock, which was necessary to make VTR time base correctors work, produces a picture sequence that repeated every four fields ( important to VTR editing) which always had problems until several years later when it was discovered that this was actually an 8 field repeat, that answered a lot of questions.

The funniest was yet to come, Bruch blanking which was unique to P.A.L. and was engineered into the replay servo lock of all VTR’s and that was it’s only use, but remove it at your peril or VTR will be in trouble. So enter RCA with the world’s first portable TV camera The RCA TK-76, which weighed 19.8 pounds without lens or battery (yes bloody heavy) this featured the first single colour SPG chip, which really was a giant step in technology at the time except it was without Bruch Blanking, I still remember the engineer flying in from the States to sort the problem and find out why VTR were unhappy and after an in-depth explanation on P.A.L. asked “Who is this Brunch guy anyway at the top of his voice (pronouncing it as just that Bunch as in Lunch), you could hear a pin drop in what was normally an area that was anything but quiet.

The 70’s still had test card transmissions in between broadcasting hours and of course that had to be redesigned for Colour.

The first Colour Test Card, the centre picture of Carole was reversed so that she would not be recognised

Yes some of you will remember Carole Hersee the most aired face in British TV history the young lady in the middle of the Test Card who could be seen playing noughts and crosses.

Now 58, she says: “I got irritable, apparently. Because every time they wanted to take another photograph, I was eating!” Her Dad Bob Hersee would have none of it, he was pushing hard for his test card to be adopted and the centre picture had some vital elements, one being the delicate flesh colour of his daughters skin, which is very useful for colour saturation settings and the Noughts and Crosses board which was helpful for setting the static convergence of the original delta gun sets.

For both BBC1 and ITV, an agreed official joint launch of colour broadcasts was agreed for Saturday, November 15, 1969.

A concert by singer Petula Clark at the Royal Albert Hall was the first official colour programme on BBC1. It was aired at midnight, the exact time the colour broadcasting licence began. It is also rumoured that apparently the Comic Dick Emery, was also taken aback at his own yellow teeth after seeing them in colour, he had covered them with white plastic.

The BBC mobile Outside Broadcast Control Rooms all had CMCR with sequential numbers as the evolved so presumably Wimbledon was televised with CMCR 1they are all documented at http://www.tvobhistory.co.uk/bbc-cmcrs---colour.html

What’s left, of these early days well there are still some early video tapes around, the oldest dates back to 1966 and is thought to be a test recording of ITV’s London Palladium Show, hosted by Jimmy Tarbuck in 1966.

It was transmitted in Black and white, but ATV used it as a dry run for an American series , so two sets of cameras recorded the performance simultaneously one set recording it in 525 NTSC colour

In the digital age, there must be some zeros! BBC CMCR (Colour Mobile Control Room

So 50 years of colour we have seen a lot of changes, probably mostly to the flat panel screens we all now watch it on and the digital delivery, well P.A.L. stood us in good stead it was never going to make it into wide screen, and analogue as it was, it was not ideal for video production and in particular multi generation VTR, but it got us started and well, £2m well spent, thank you David Attenborough the man at the helm in BBC 2 who pushed hard to get it started and for those of you that remember his Zoo Quest series, which was first broadcast in 1954, and was previously thought to have been filmed in black and white. Well it was filmed in 16mm colour and was transmitted that way on BBC4 on the 11 may, so again David Attenborough’s a colour TV pioneer.

Contents ^

USA $27.00 year, Canada / Mexico $27.00 year DX $37.00 year (US $) Cyber: $15 year.

Published by ATV Quarterly Visa, M/C, AMEX PayPal via Cheques or Money Orders to Internet: www.atvquarterly.com P.O.Box 1594 Crestline CA 92325 email: wa6svt@atvquarterly.com tel (909) 508-6887

Contents ^

Results IARU ATV activity weekend/contest 2017

Published 11th July 2017

Chris van den Berg PA3CRX, chairman VHF-and-above committee

Many stations joined the IARU ATV activity weekend/contest in June.

I especially call it ‘activity weekend’ since that is for the majority of the participants the most important reason to join. To have the highest score is for most of us not important. In fact, not everyone and every country have the same possibilities to reach the highest score:

- different authorisation of band usage,

- different troposphere conditions,

- flat country or with mountains,

- path over sea,

- difference in antenna allowance,

- possibility to go portable,

- etc.

However, this activity is all about joining and having fun! This is understood by you, many send in their logs, some even with a very limited number of contacts.

The other purpose is to stimulate ATV activity, experimenting, showing our presence on the bands; ‘use it or loose it’.

This is very well understood by countries that joined and send in their logs for this activity weekend for the first time (or since a log time): welcome!

Highlights:

- band usage is very different in individual countries. While in one country almost all contact were made on 70 cm, in an other country almost all contact were made in the 23 cm band.

- ATV bands from 70 cm up to 1.2 cm are used, several stations operated on all seven bands,

- D-ATV as well as analogue,

- Enormous distances!

- Several portable stations,

- five stations operating from more then one location,

- limited number of contacts between countries.

The number of stations that send in their logs:

- in 2014: 33,

- in 2015: 42,

- In 2016 52,

- In 2017: 95! (operated from 100 locations).

This increase could have been the result of active promoting to ATV by several countries. I asked the VHF-managers to publish this ATV activity in their local HAM magazines but unfortunately it was not always honoured despite all attention that is given to weak signal contests. A shame that some countries even made confusion with expired log sheets and rules on their website, even mentioning wrong date/duration of the activity.

A total 719 lines in the logs shows a lot of band usage during this activity.

As you can see IK3HHG has the most overall points this year. Congratulations with this result!

Why not consider every ATV contact (especially with a new station) as a winning contact! So in fact, congratulations to everyone with your reached results.

In the tables you will find the details for every individual participant per band and the totals. Also included is the map with all participating ATV stations in the ATV contest of 2017.

The results could also be found at https://vhf-uhf.veron.nl/wp-content/uploads/2015/08/IARU-ATV-results-2017.pdf and likely soon on the IARU R1 website.

I will send certificates to some stations by email today. If you did not receive it and you would like to have one with your score on it, please do not hesitate to contact me and ask.

Check-out www.dxspot.tv especially during the contest (you can look back half a year). Handy to find each other, also on other days then the activity weekend. In several countries there are more ATV activity weekends, spread over the year.

Hopefully you all enjoyed this ATV activity weekend and spread it around so we have next year even more participants. To get others enthusiastic, you have to SHOW that ATV is interesting and fun!

Not only in HAM meetings or ATV magazine but you could send also a picture with your ATV activity and some additional text to your national HAM magazine. It is obvious that ATV articles in most national HAM magazines are often hard to find, while there is a lot of ATV activity in their country. If you want to have more ATV interested stations, you need to bring ATV under attention by yourself! Start with a (small) description of your station, experiment or experience (including picture) sending to the editor of your local HAM magazine.

Weak signal activities like contests are often in the picture while they use only limited periods a very small portion of the bands. We should make them aware that ATV stations are the heavy band users that they need to protect the bands. (Besides that ATV is fun and it is easy and cheap to start with).

If you need the activity weekend/contest results in other format (Excel, Word) for publication, please let me know.

70 cm

No.

Call

Points

BestDX

QTH

Distance

1

F9ZG/P

6799

F1AHR

IN94VO

487

2

F5AGO

5683

F6BGR

JO00SC

395

3

F1AEA/P

3143

F9ZG/P

IN98JW

385

4

F6BGR

2758

F5AGO

JN06DP

395

5

F6AQO

2687

F9ZG/P

IN98JW

269

6

F6ESU

2509

F5AGO

JN06DP

393

7

F1AIW

1905

F1CSY

JN03SK

377

8

PE1EZU

1265

ON7ARQ

JO10VX

157

9

G8GTZ/P

938

F9ZG

IN98JW

201

10

F5MKM

845

F5AGO

JN06DP

187

11

G8GKQ/P

803

G3KKD

JO02CF

127

12

PA3DLJ

706

PE1EZU

JO22LE

150

13

PA7HV

688

PA3CGG

JO22ID14DS

102

14

G4KLB

660

F9ZG

IN98JW

205

15

PA0BOJ

628

PA3DLJ

JO20VW

83

16

PA3CGG

590

PE2TV

JO32GH

128

17

G7JTT/P

530

F9ZG

IN98JW

236

18

PE1POA

527

PA0BOJ

JO21ON17JV

75

19

G3KKD

493

G8GKQ/P

IO91IN

127

20

PE1ITR

459

PE1EZU

JO22LE

88

21

HB9TV/P

412

F5AJJ

JN27LH

130

22

M0DTS/P

331

G1LPS

IO94EQ

95

23

PE2TV

309

PA3CGG

JO22ID

126

24

G1LPS

292

M0DTS/P

IO93OX

95

25

PE1APH

292

PE1EZU

JO22LE93OW

100

26

PA9DX/A

291

PE1ITR

JO21QK

82

27

G0WFT

272

G8GKQ/P

IO91IN

66

28

HB9IAM

208

HB9TV/P

JN36GU44OK

77

29

PE1ASH

207

PE1POA

JO22RF82CP

42

30

PA1AS

154

PA7HV

JO21TK

60

31

PA3CWS

95

PA3CGG

JO22ID14DS

54

32

G4GUO

82

G8GKQ/P

IO90LU

41

33

PA3CRX

70

PE1ASH

JO22KF

34

34

PE1MPZ

57

PA3CGG

JO22ID14DS

30

35

PA1G

54

PE1EZU

JO22LE93OW

27

36

PE1CVJ

50

PA9DX/A

JO22MD14UR

19

No.

Call

Points

BestDX

QTH

Distance

37

EA7KA

10

EA7GLU

IM86SU

5

38

EA7GLU

10

EA7KA

IM86SU

5

39

PA1EBM

10

PA1AS

JO20XW

5

23 cm

No.

Call

Points

BestDX

QTH

Distance

1

IK3HHG

7340

IW6ATU

JN63QN

284

2

PE1EZU

4552

PA3DLJ

JO20VW

149

3

F9ZG/P

4144

F5AGO

JN06DP

278

4

PA3CGG

3388

PE1NKT

JO33EE

163

5

ED4SHF/6

3328

EA3UM

JN01XG

211

6

F5AGO

3146

F1DBZ

JN09DM

319

7

PE2TV

3052

PA3CGG

JO22ID

126

8

PA0BOJ

2482

PA1AS

JO20XW

89

9

PE1POA

2244

PE1NKT

JO33EE

123

10

IW6ATU

2244

IK3HHG

JN65AW

284

11

PA9DX/A

2222

PA1AS

JO20XW

149

12

PA3DLJ

2000

PE1EZU

JO22LE

150

13

M0DTS/P

1988

G3NWR/P

IO93AD

120

14

I2MUT

1988

IK3HHG

JN65AW

208

15

PA7HV

1880

PA3CGG

JO22ID14DS

102

16

EA9MH

1456

EA7GLU

IM86SU

182

17

PE1ASH

1420

PA3CGN

JO32MG

148

18

IW4CPP

1360

IK3HHG

JN65AW

205

19

PA1AS

1334

PA9DX/A

JO22MD

148

20

EA3XU

1312

ED4SHF/6

JN10WB63LT

210

21

PE1APH

1276

PE1EZU

JO22LE93OW

100

22

IW2EYM

1186

IK3HHG

JN65AW

144

23

G8GTZ/P

1124

F9ZG

IN98JW

201

24

F6AQO

1118

F9ZG/P

IN98JW

269

25

EA3BAE

1112

ED4SHF/6

JN10WB63LT

203

26

G3NWR/P

1064

M0DTS/P

IO93OX

120

27

IK4ADE

1044

IK3HHG

JN65AW

205

28

I2CIC

1036

IK3HHG

JN65AW

154

29

G1LPS

1012

M1EGI/P

IO93FL

134

30

EA3UM

1012

ED4SHF/6

JN10WB63LT

211

31

M1EGI/P

1002

G1LPS

IO94EQ

136

32

IW6OCN

946

IW6ATU

JN63QN

183

33

EA3DZN

912

ED4SHF/6

JN10WB63LT

208

34

PE1MPZ

904

PA0BOJ

JO21ON17JV

54

35

G7AVU

888

G3NWR/P

IO93AD

82

36

HB9TV/P

824

F5AJJ

JN27LH

130

37

IW2MBA

780

I2MUT

JN44XS

83

38

EA7GLU

768

EA9MH

IM85MG

182

39

PA3CRX

662

PA3CGG

JO22ID14DS

48

40

PA3CWS

632

PA3CGG

JO22ID14DS

54

41

PE1CKK

628

PA3CGG

JO22ID14DS

34

No.

Call

Points

BestDX

QTH

Distance

42

IZ3ZUB

622

IW6ATU

JN63QN

284

43

PE1BR

590

PE1EZU

JO22LE

131

44

DK1UP

580

DD4PQ

JN39TT

70

45

PE1ITR

568

PE1EZU

JO22LE

88

46

G8GKQ/P

528

G4CPE

IO91SW

71

47

PE1CVJ

508

PE1MPZ

JO22NB02NU

30

48

F6ESU

488

F1RJ

JN18AT

122

49

EA7KA

404

EA9MH

IM85MG

182

50

IW6CHN

372

IW6OCN

JN72DB

115

51

F1AIW

322

F1AHH

IN95QQ

139

52

HB9IAM

308

HB9TV/P

JN36GU44OK

77

53

G8VAT/P

228

M0DTS/P

IO93OX

39

54

IW3IDP

196

IK3HHG

JN65AW

49

55

EA3CUE/P

180

EA3XU

JN11CK02EI

30

56

IW3HKW

180

IK3HHG

JN65AW

45

57

SM0OFV

180

SM0VPJ

JO89VK33

16

58

SM0WLL

172

SM0VPJ

JO89VK33

21

59

PA1G

160

PE1EZU

JO22LE93OW

27

60

SM0VPJ

148

SM0WLL

JO89WF29

21

61

G8EOP

128

M0DTS/P

IO93OX

64

62

EA3FVI

100

EA3XU

JN11CK02EI

25

63

EA3ABZ

100

EA3XU

JN11CK02EI

25

64

IK6DTA

96

IW6OCN

JN72DB

48

65

SA0CCA

76

SM0OFV

JO99AI27

13

66

G4KLB

40

G8GTZ/P

IO80WP

20

67

G0WFT

36

G8GTZ/P

IO91RU

9

68

I6CXB

32

IW6ATU

JN63QN

8

69

PA1EBM

20

PA1AS

JO20XW

5

13 cm

No.

Call

Points

BestDX

QTH

Distance

1

PA3CGG

7080

PA3CGN

JO32MG

162

2

PA0BOJ

4755

PA3DLJ

JO20VW

83

3

IK3HHG

3940

IW6ATU

JN63QN

284

4

PE1ASH

3550

PA3CGN

JO32MG

148

5

PE2TV

3185

PA3CGG

JO22ID

126

6

PE1EZU

3105

PE2TV

JO32GH

106

7

PE1POA

2700

PA0BOJ

JO21ON17JV

75

8

PA7HV

2415

PA3CGG

JO22ID14DS

102

9

PA9DX/A

2160

PA0BOJ

JO21ON

66

10

PE1MPZ

1850

PA0BOJ

JO21ON17JV

54

11

M0DTS/P

1500

G8VDP

IO93GM

67

12

PE1BR

1500

PA3CGG

JO22ID

148

13

PA3DLJ

1490

PA0BOJ

JO21ON

80

14

IW6ATU

1420

IK3HHG

JN65AW

284

15

PE1CKK

1420

PA3CGG

JO22ID14

34

16

PA3CRX

1260

PA3CGG

JO22ID14DS

48

No.

Call

Points

BestDX

QTH

Distance

17

PE1CVJ

1140

PE1MPZ

JO22NB02NU

30

18

PA3CWS

1115

PA3CGG

JO22ID14DS

54

19

DK1UP

750

DC8UG

JO30UH

42

20

G1LPS

605

M0DTS/P

IO94DF

51

21

IW3IDP

490

IK3HHG

JN65AW

49

22

G3NWR/P

400

G3UVR

IO83KH

80

23

PA1AS

170

PA3DLJ

JO20VW

12

24

PA1EBM

50

PA1AS

JO20XW

5

9 cm

No.

Call

Points

BestDX

QTH

Distance

1

G1LPS

1160

M0DTS/P

IO94DF

51

2

PA3CGG

1140

PA3CRX

JO22QE51EF

48

3

PE1EZU

870

PA3CRX

JO22QE

26

4

PE1ASH

725

PA3CRX

JO22QE51EF

35

5

PA3CRX

720

PA3CGG

JO22ID14DS

48

6

PE1CKK

660

PE1CGG

JO22ID14

34

7

M0DTS/P

510

G1LPS

IO94EQ

51

8

PE1CVJ

420

PA3CGG

JO22ID14DS

19

9

G3NWR/P

120

G4CBW

IO83UB

24

10

PA3CWS

30

PA3CRX

JO22QE

6

6 cm

No.

Call

Points

BestDX

QTH

Distance

1

IK3HHG

2560

S58RU

JN65WM

150

2

PA3CGG

1700

PE1POA

JO22RF82CP

56

3

PE1POA

1250

PA3CGG

JO22ID14DS

56

4

PE1EZU

1240

PE1FOT

JO21MU05LT

36

5

PE1ASH

1090

PE1POA

JO22RF82CP

42

6

PE1CKK

1010

PE1CGG

JO22ID14DS

34

7

PA9DX/A

660

PA3CGG

JO22ID14DS

23

8

G1LPS

510

M0DTS/P

IO94DF

51

9

M0DTS/P

510

G1LPS

IO94EQ

51

10

PA3CRX

480

PA3CGG

JO22ID14DS

29

11

PE1CVJ

420

PA3CGG

JO22ID14DS

19

12

G8GKQ/P

400

G8GTZ/P

IO80WP

80

13

G8GTZ/P

400

G8GKQ/P

IO90LU

80

3 cm

No.

Call

Points

BestDX

QTH

Distance

1

IK3HHG

5715

I2MUT

JN44XS

208

2

I2MUT

5390

IK3HHG

JN65AW

208

3

IW2MBA

1160

I2MUT

JN44XS

83

4

M0DTS/P

1160

G7AVU

IO93OJ

65

5

I2CIC

1050

I2MUT

JN44XS

54

6

PA3CGG

775

PE1MPZ

JO22NB02NU

30

7

IW2EYM

660

IW2MBA

JN55GJ

33

8

G7AVU

650

M0DTS/P

IO93OX

65

9

G3NWR/P

640

G3UVR

IO83KH

80

10

PE1EZU

590

PA3CGG

JO22ID14DS

22

11

IW4CPP

560

I2CIC

JN55FC

51

12

PE1ASH

555

PE1MPZ

JO22NB02NU

23

13

G1LPS

510

M0DTS/P

IO94DF

51

14

PA9DX/A

455

PA3CGG

JO22ID14DS

23

15

IK2ARZ

420

I2MUT

JN44XS

42

16

PE1MPZ

400

PA3CGG

JO22ID14DS

30

17

IW3IDP

245

IK3HHG

JN65AW

49

18

PE1CVJ

230

PE1EZU

JO22LE93OW

15

19

IZ3UOF

205

IK3HHG

JN65AW

41

20

IU3IQY

205

IK3HHG

JN65AW

41

21

IZ3ALW

205

IK3HHG

JN65AW

41

22

IZ3NVR

205

IK3HHG

JN65AW

41

23

EA3CUE/P

150

EA3XU

JN11CK02EI

15

24

EA3XU

150

EA3CUE/P

JN11DM

15

25

PA1AS

110

PA3DLJ

JO20VW

12

26

IU3IOU

70

IK3HHG

JN65AW

14

27

PA3DLJ

60

PA1AS

JO20XW

12

28

PE1BR

50

PE1IWT

JO32KF

5

29

EA7KA

50

EA7GLU

IM86SU

5

30

PA1EBM

50

PA1AS

JO20XW

5

31

EA7GLU

50

EA7KA

IM86SU

5

32

PA0RWE

25

PA3CGG

JO22ID14DS

5

1.2 cm

No.

Call

Points

BestDX

QTH

Distance

1

PE1EZU

530

PA3CGG

JO22ID14DS

22

2

PA3CGG

515

PA3CRX/P

JO22MF85MK

29

3

G1LPS

510

M0DTS/P

IO94DF

51

4

M0DTS/P

510

G1LPS

IO94EQ

51

5

PE1ASH

320

PA3CGG

JO22ID14DS

15

6

PA3CRX

235

PA3CGG

JO22ID14DS

29

7

PE1CVJ

230

PE1EZU

JO22LE93OW

15

Totals

No.

Call

IARU score

1

IK3HHG*

19555

2

PA3CGG*

15188

3

PE1EZU

12152

4

F9ZG/P*

10943

5

F5AGO

8829

6

PE1ASH

7867

7

PA0BOJ

7865

8

I2MUT*

7378

9

PE1POA

6721

10

PE2TV

6546

11

M0DTS/P*

6509

12

PA9DX/A

5788

13

PA7HV

4983

14

G1LPS

4599

15

PA3DLJ

4256

16

F6AQO

3805

17

PE1CKK

3718

18

IW6ATU

3664

19

PA3CRX

3427

20

ED4SHF/6*

3328

21

PE1MPZ

3211

22

F1AEA/P

3143

23

PE1CVJ

2998

24

F6ESU

2997

25

F6BGR

2758

26

G8GTZ/P

2462

27

F1AIW

2227

28

G3NWR/P

2224

29

PE1BR

2140

30

I2CIC

2086

31

IW2MBA

1940

32

IW4CPP

1920

33

PA3CWS

1872

34

IW2EYM

1846

35

PA1AS

1768

36

G8GKQ/P

1731

37

PE1APH

1568

38

G7AVU

1538

39

EA3XU

1462

40

EA9MH

1456

41

DK1UP*

1330

No.

Call

IARU score

42

HB9TV/P*

1236

43

EA3BAE

1112

44

IK4ADE

1044

45

PE1ITR

1027

46

EA3UM

1012

47

M1EGI/P

1002

48

IW6OCN

946

49

IW3IDP

931

50

EA3DZN

912

51

F5MKM

845

52

EA7GLU

828

53

G4KLB

700

54

IZ3ZUB

622

55

G7JTT/P

530

56

HB9IAM

516

57

G3KKD

493

58

EA7KA

464

59

IK2ARZ

420

60

IW6CHN

372

61

EA3CUE/P

330

62

G0WFT

308

63

G8VAT/P

228

64

PA1G

214

65

IZ3NVR

205

66

IZ3UOF

205

67

IU3IQY

205

68

IZ3ALW

205

69

IW3HKW

180

70

SM0OFV*

180

71

SM0WLL

172

72

SM0VPJ

148

73

PA1EBM

130

74

G8EOP

128

75

EA3ABZ

100

76

EA3FVI

100

77

IK6DTA

96

78

G4GUO

82

79

SA0CCA

76

80

IU3IOU

70

81

I6CXB

32

82

PA0RWE

25

No.

Call

IARU score

1

IK3HHG*

19555

2

PA3CGG*

15188

3

PE1EZU

12152

4

F9ZG/P*

10943

5

F5AGO

8829

6

PE1ASH

7867

7

PA0BOJ

7865

8

I2MUT*

7378

9

PE1POA

6721

10

PE2TV

6546

11

M0DTS/P*

6509

12

PA9DX/A

5788

13

PA7HV

4983

14

G1LPS

4599

15

PA3DLJ

4256

16

F6AQO

3805

17

PE1CKK

3718

18

IW6ATU

3664

19

PA3CRX

3427

20

ED4SHF/6*

3328

21

PE1MPZ

3211

22

F1AEA/P

3143

23

PE1CVJ

2998

24

F6ESU

2997

25

F6BGR

2758

26

G8GTZ/P

2462

27

F1AIW

2227

28

G3NWR/P

2224

29

PE1BR

2140

30

I2CIC

2086

31

IW2MBA

1940

32

IW4CPP

1920

33

PA3CWS

1872

34

IW2EYM

1846

35

PA1AS

1768

36

G8GKQ/P

1731

37

PE1APH

1568

38

G7AVU

1538

39

EA3XU

1462

40

EA9MH

1456

41

DK1UP*

1330

No.

Call

IARU score

42

HB9TV/P*

1236

43

EA3BAE

1112

44

IK4ADE

1044

45

PE1ITR

1027

46

EA3UM

1012

47

M1EGI/P

1002

48

IW6OCN

946

49

IW3IDP

931

50

EA3DZN

912

51

F5MKM

845

52

EA7GLU

828

53

G4KLB

700

54

IZ3ZUB

622

55

G7JTT/P

530

56

HB9IAM

516

57

G3KKD

493

58

EA7KA

464

59

IK2ARZ

420

60

IW6CHN

372

61

EA3CUE/P

330

62

G0WFT

308

63

G8VAT/P

228

64

PA1G

214

65

IZ3NVR

205

66

IZ3UOF

205

67

IU3IQY

205

68

IZ3ALW

205

69

IW3HKW

180

70

SM0OFV*

180

71

SM0WLL

172

72

SM0VPJ

148

73

PA1EBM

130

74

G8EOP

128

75

EA3ABZ

100

76

EA3FVI

100

77

IK6DTA

96

78

G4GUO

82

79

SA0CCA

76

80

IU3IOU

70

81

I6CXB

32

82

PA0RWE

25

* most points in their country.

This map contains all locations that are in the logs. Five stations were active from two different locations.

Next IARU ATV contest date: 9 and 10 June 2018

Starts Saturday 12:00 UTC, ends Sunday 18:00 UTC.

IARU rules:

http://www.iaru-r1.org/images/VHF/atv/IARU_ATV_contest_rules_version_2015.pdf

logsheet:

http://www.iaru-r1.org/images/VHF/atv/ATV_contest_log_-_ATV_yourcall_YYYYMMDD.xls

Chris van den Berg PA3CRX VERON Chairman of VHF-and-above IARU ATV contest manager

Contents ^

Micro Corner - Node MCU BASIC and I^2C control

By Trevor G8CJS

Node MCU Module and pin out

In CQ-DATV issue 43 we introduced the Node MCU micro controller and showed how to install a resident BASIC programming language that enables you to create simple programmes that can be edited in this high level language. The unit talks to your PC browser via WiFi, and can be powered from a USB socket.

Because this is an ATV magazine we based all the projects so far on ATV applications and two of the most popular have involved using the I^2C bus and its built in instruction set for controlling the I^2C bus - see CQ-DATV 46 and CQ-DATV 49 (both in the CQ-DATV library) http://cq-datv.mobi/ebooks.php

The first project was simple internet control of a set of LED’s that could be changed into drivers for an ATV repeater for video switching and all the housekeeping.

In CQ-DATV 49 we expanded this to rotating a RX aerial for a repeater which would greatly improve any ATV repeaters coverage area as opposed to the usually implemented Omni directional aerial. In CQ-DATV 51 we will be reading the I^2C bus in order to look at a video detector to see if anyone requires access to a repeater.

All the projects use the I^2C bus of the micro to drive a PCF 8547A I^2C expander port, we may have skipped along a little too fast as there has been one or two questions, although I^2C is heavily documented on the internet. So let’s try and clear up one or two points on this port chip which is now available as a pre-wired module, (for those of you that have lost your soldering iron).

Pre-bought module with A0 A1 A2 switches to set the address

It connects to the NODE MCU module via the conventional two wire I^2C bus. This is an open collector bus and can be daisy chained around many of these expander chips. It does require a pull-up resistor for both the SDL and SCL connection as the outputs are open collector, but only one on each leg regardless of how many port chips are daisy chained together on the I^2C bus.

I^2C bus interconnect

The expander chips have a unique address so that the bus can identify each chip. This is a 7bit address, four bits being locked into the chip, and three bits brought out to external pins on the chip so the I^2C address can be externally selected.

The four internal address connections are A7 to A4. For the PC8574 they are hard wired as follows

A7 Low,

A6 High,

A5 Low

A4 Low.

The PCF 8574A is different they are

A7 Low,

A6 High,

A5 High

A4 High,

Then for both chips A3 A2 A1 are wired to pins 1, 2, 3, so they can be set by the user as either high or low.

The chart documents the addresses for both the PCF 8574 and the PCF 8574A for all the available address locations.

A0

A1

A2

DECIMAL PCF 8574

HEX PCF8574

DECIMAL PCF 8574A

HEXPCF 8574A

0

0

0

32

0x20

56

0x38

1

0

0

33

0x21

57

0x39

0

1

0

34

0x21

58

0x3a

1

1

0

35

0x22

59

0x3b

0

0

1

36

0x24

60

0x3c

1

0

1

37

0x25

61

0x3d

0

1

1

38

0x26

62

0x3e

1

1

1

39

0x27

63

0x3f

The I^2C addresses available to the PCF 8574AP and PCF 8574 as set by A0 A1 and A2

Three PCF 8574A I^2C port chips configured at three different addresses

A nice way to check the hardware is working and that you have the correct addresses for all the hardware is to ask the micro to check it for you and report back the address at which an I^2C device is located. The following BASIC programme will do that for you.

for address = 1 to 127

i2c.begin(address)

stat = i2c.end()

if stat < 1 then

' print stat

wprint "Found I2C device at address: 0x" & hex(address)

wprint " - > " & address

wprint " <br/ >"

endif

next

wait

Just copy and paste this code into the edit page, save and run. This was the result for the above configuration.

Nice to be proved right by software.

There are a couple of other complications to the I^2C bus, that you would only need to know if you were programming in machine code, but is taken care of in EPS BASIC.

There is a unique timing sequence on the clock and data bus SCL SDA. The data line is always stable when the clock is in a high state indicating that the data on the bus is valid. The data only changes when the clock is low.

A start sequence is different and is one of two special sequences defined for the I^2C bus, the other being the stop sequence. The start sequence and stop sequence are special in that these are the only places where the SDA (data line) is allowed to change while the SCL (clock line) is high.

This again is easy for the BASIC programmer

- i2c.begin(address) sends out the start sequence

- i2c.end() sends out the stop sequence

The last thing again is the direction of the data on the I^2C bus which is a little more complex to grasp. The I^2C address is seven bit, but converted to 8 by moving all the 1’s and 0’s one step towards the MSB so x 1 1 0 1 1 1 = 55 decimal would become 1 1 0 1 1 1 1 x =222 in decimal (BASIC uses Decimal not hex). This frees up the LSB x in which is placed 1 for a read direction of data and 0 for a write direction of data so read addresses are always odd numbers and read addresses are always even.

Again the address shift and the setting or resetting of the MSB is taken care of by simply using either i2c.write(address) and i2c.read () no address shifting is required, just use the address in the chart or the address delivered by the above code. BASIC takes care of all these problems for you and produces a simple to understand set of instructions that can be changed by simple key strokes, saved and stored and will deliver you a programme with less brain pain than machine code programming of the I^2C bus.

All you have to do is learn how to use the instruction set in the manual. Although difficult at first because of a lack of examples, this will soon become second nature. Should you mess up the syntax and create an error the line number of the problem or problems will be pointed out to you when you run the programme, return to the edit mode, correct the syntax and try again. The manual is on-line at https://docs.google.com/document/d/1EiYugfu12X2_pmfmu2O19CcLX0ALgLM4r2YxKYyJon8/pub#h.o9kamrmfwc3u

This is in Google documents and you might have to create a login to see it.

So what is holding you back the NODEMCU modules cost about the same as a PIC, they have built in Wi-FI, 4MB of non volatile memory and can be programmed in seconds, with the biggest plus of all, find a BASIC programme (lots on the net and more in CQ-DATV micro corner). Copy and paste it into the edit page, save and run and if you have messed up it will point out rather diplomatically where the error is. Not bad for module costing under £3

Some entertaining and useful links

- Flash Link https://www.esp8266basic.com/download.html

- Clock Software https://www.esp8266basic.com/graphic-clock-example.html

- BASIC Examples https://www.esp8266basic.com/examples.html

- TV TX 1 VHF TV https://www.youtube.com/watch?v=SSiRkpgwVKY

- TVTX2 VHF TV http://hackaday.com/2016/03/01/color-tv-broadcasts-are-esp8266s-newest-trick/

- Forum Help http://www.esp8266.com/viewtopic.php?f=40&t=6732

- Driving an LED light strip https://www.youtube.com/watch?v=7Dv70ci-MOw

- Nice demo https://www.youtube.com/watch?v=fVpAN3adK9A

Contents ^

TV Amateur is a German Language ATV Magazine It is published 4 times a year and if you would like to subscribe go to http://agaf-ev.org/

Contents ^

A Digital World - An Introduction to DATV

By Richard Carden - VK4XRL

It has been some time since I last wrote as I have been busy building the DVS receiver and Ports Down transmitter more on those later. Also over the past few months we have seen many emails from people who want to get started in DATV or to build a repeater. Having this information available via CQ-DATV is a great starting point where people can learn from the experience of others and that includes myself. I will try and give as much information as I can from our experiences here in Australia. I won’t be going into the technical aspects as this has been covered by others like the technical talk articles at http://www.datv-express.com/#Item4 and those of http://kh6htv.com/application-notes/.

We started to transmit digital going back to 2002 and brought some boards from SR-Systems for 23/13cm. These were the first digital transmissions here in Australia and looked very good. We just opted for 1250/1283 MHz and set the other parameters for a 10 MHz bandwidth.

However better utilisation can be had my dividing the 23cm band into 3 sections and using a 6 MHz bandwidth (see picture). 23cm DATV using DVB-S is only used as far as I know in Australia for inputs to the repeaters. We used a Humax receiver modified with a video present indicator to trigger the repeater controller. It has been interesting while gathering information regarding DVB-S setting as used around Australia, USA, UK and Europe that a lot of different symbol rates, PID’s have been used. One wonders why when most are using only one transport stream where a bandwidth of 5 MHz would do for SD.

However better receivers are now available and we have found the Strong brand to be very good. The STR 4950E http://strong.com.au/hd-satellite-receivers/high-definition-mpeg4-dvbs-2-digital-satellite-receiver-with-record-function-via-usb is an example that has the added advantage of a signal indicator so you only need a relay and transistor to apply an earth (our case) to the controller, also it has another advantage in that DVB-S2 can be received for those wanting to experiment further. Like using the BATC Postsdown DATV transmitter. More on that later.

A newer receiver has come to light with the MiniTioune receiver project, developed by Jean-Pierre F6DZP, consisting of a home constructed hardware on a PCB which then interfaces via a standard USB 2.0 port to a Windows PC running the MiniTioune software. It is a good receiver but would like to see more information as to the regards of use in a repeater? And what computer interface is been used? Like what happens after a power drop out and resetting the receiver and computer?

The other down falling as I see it is no audio monitoring via bar graphs of levels from the dual channels and the setting of a reference level? On my part without the right equipment, I have used tone from our Optus satellite as a reference and adjust levels accordingly.

We have been transmitting digital for the past 6 years using DVB-T on 446.5 MHz were we decided to at a very early stage to go for the same standard as used by the FTA systems as used in this country. The only difference was we went for QPSK which gives slightly better results and helps when running higher power amplifiers. A black chip will give you around 5 to 6 watts output (IE the 6db rule). So for my 100w power amplifier I would expect around 25 Watts output. To receive the repeater you’ll need a STB or Digital Television that enables you to programme manually the required frequency. Again we have found that the Strong band will cover our requirements and one of my choices is the STR 5432. http://strong.com.au/set-top-boxes/hd-mpeg4-with-record-function-to-usb. It also covers MPEG4 which is another added advantage (re use of PortsDown).

I know the problems in the UK and parts of Europe don’t allow for wide bandwidths associated with DATV on 70cm so I apologise in that regard. Note that QAM 16 and QAM 64 are only needed to be used for where greater bitrates associated with multiple transport streams are required, however QPSK will allow for dual transports if and when required.

The subject of antennas for transmission will now arise and will be depended on where you situate your repeater in relation to those going to use it. We use dual yagi antennas to cover most of the Brisbane area from our repeater situated some Km north west of the CBD area. I for one personally like the phased array which has a broader bandwith. Shown is my prototype see CQ-DATV 21.

If omi direction antennas are required then the phasing of a couple of the big wheel antennas or even the Alford slot maybe the answer.

So where do you start, firstly you need to decide what digital platform you want to use. You will need to take into account what system is being used in your area to determine if DVB-T or DVB-S should be used.

My personal preference would be if it’s a new repeater system would be to go with DVB-T. The modulators are readily available for this system and there are not a lot for DVB-S, however commercial equipment is coming available from time to time that could be utilised. DVB-T digital modulators that I have used are:-

- SR-System – check with Stefan on your requirements http://sr-systems.de/content.php?show=Produkte&lng=eng&style=std

- Clearview from Kristal - https://www.kristalelectronics.com/digital-products/digital-modulators.html

- PV! – I have some problems with this unit in that it reboots on loss of signal and distortion on audio when feed from low impedance outputs from commercial SDA’s. http://www.pvistore.com/hdmi-mod/

- Hide’s - http://www.hides.com.tw/index_eng.html

70 MHz IF 23cm FM Transmitter

The build of a repeater or home TX is a personal issue and will depend on individual skills. I personally like to build in module form in a rack format. I don’t like to put all my eggs in one basket, however having said that there are occasions where space becomes the major consideration and a one rack repeater system excluding receivers maybe warranted. Whatever the case I would make dual units for easy replacement as it’s normally a long drive to most repeater sites. The test-cards and Idents can be happily provided for by WD media players these units when setup properly will reset back to your setup after power glitches. Video and audio switchers can be roll your own or again commercial units as found on eBay. I like the idea of providing VDA’s on the inputs if you have the space to do so, especially the FM receiver input as we are using only half the normal bandwidth of 18MHz and therefore the output would be around half a volt P/P so a VDA will reset that to one volt P/P. Sometimes you may need to fit a video filter to the receivers output to reduce and indication of audio sub-carries. This of cause depends on the FM receiver that you use. Also one thing that should be added is a way to monitor levels both audio and video, the aim should be to make the repeater as transparent as possible.

One rack unit 4 x 1 Repeater Controller

WD Media Player wired as plug in Board

PortsDown DATV Transmitter experience, the overall project was a great Idea, however it was made basically for the UK market and trying to get information wasn’t initially available from Wiki. This has improved somewhat which makes it a lot easier to follow. My interest in building it was just for a cheap DVB-S TX so that anyone could use it to go digital and as an exciter for 10Ghz. I did run into a problem where I had placed a space when resetting the frequency which stuffed the system, however Dave found the problem and re coded the SD card. Since then I have made a spare just in case. The biggest downfall I feel is that of the audio as of the time writing this no audio is available with the Easy-Cap input.   Dave G8GKQ (https://wiki.batc.tv/index.php?title=User:G8GKQ&action=edit&redlink=1) is now working on this and other updates so you need to look here https://wiki.batc.tv/Software_capabilities_and_issues. As more people get to build and test the unit most bugs will disappear and other add-ons may surface.

Reference: http://dvbcalculator.altervista.org/

Reference: http://dvbcalculator.altervista.org/

Contents ^

Building the Portsdown in the real world

By Bob Dyer - G1XIE

This is a summery of my personal experience with building the Portsdown digital ATV transmitter.

I would like to pass on my gratitude to everyone who designed this transmitter and let it onto the market for free. It looks like it was a LOT of work and many years of knowledge that went in to it all given away for everyone to use. This sort of selfless endeavour makes me regain faith in humanity.

As for myself I’m a dedicated analogue man. I did try digital stuff for a while but when it progressed to 16 bits and more I stopped looking. Sadly it would seem that neither my home made Acorn atom or BBC micro were suitable for doing digital TV so I had to bite the bullet and embrace 64bit logic.

Getting given an Amazon voucher from work (they finally appreciated me!) I was wondering what to do with it when I realised that I could use it to buy a Raspberry Pi and screen so I could make an entire DATV transmitter for free! I now had all the kit I needed now so started the ‘build’. It was then that I learnt I needed a memory card. No big deal, they are fairly cheep so I got one and a couple of weeks later I had a working digital transmitter!

The next ‘issue’ was I had nothing to receive it on. It wouldn’t talk to my current digital satellite receiver. Some questions on the BATC forum later and I discovered it was only good for ‘ugly’ mode. Don’t ask me, all I know is the name not what it really is. To receive it I’d need a special receiver like another raspberry Pi with a SDR dongle or a MiniTiouner. By chance I had an old raspberry Pi and a dongle so tried that. It did sort of work so I got the impression the TX was working but was all a bit slow and random so I spent the money and bought the bits for a MiniTiouner. Of course, when I went to buy then the BATC were out of stock (no offence to BATC in any way, they are running hand to mouth with little if any profit so can’t be expected to hold a warehouse of stock)

Eventually, with about another £35 gone from my bank account for a free project, I had a working MiniTiouner digital receiver.

The local computer recyclers happen to also host the GB3HV mast so I went to them to get a 19v PSU. They were very good and even though they weren’t open when I went there, just cleaning up, the gave me an old monitor or laptop PSU for very little money. This was needed so I could connect the MiniTiouner to my LNB and test it using GB3HV. I don;t have a picture of it as I made a bit of an error in the end. Having got the system working I decided to disassemble the PSU for inserting into single unit with the MiniTiouner. All went well until I accidentally brushed my hand on the de-cased PSU and found why it was covered in plastic, the internal metalwork was live. I decided then that it might be wise to get a replacement and leave to outer case on.

Now I have a known working Portsdown that I can use across the workshop, WooHoo. Now to talk to GB3HV! Errr… Nope.

OK, I really should do more research before beginning a project. “Every thing is in the Wiki” was something I’d heard several times. Sadly I’m a linear analogue person. I expect information to be set out like a book. An index page and a stack of consecutive pages there after. I can print it all out and read it cover to cover much like CQ-DATV. Wiki’s don’t seem to be like that. To my mind they are like a box of paper. You just need to know which bit of paper to search for and look at. I had no clue what I was looking for so had issues finding anything.

I’m already into this project with more time and cost that I’d planned so I bite the bullet, got to the BATC shop and order one of everything under the Portsdown heading. At least now I should be able to get something I can use properly and fully. I’ll read the info for each board when it turns up and see where it is used.

Thankfully Noel, G8GTZ, who was dealing with my order could see what I’d done and removed at least one bit that I apparently had no use for and refunded the cost. So now I had all the boards and hard to get bits I could order all the other little bits. Thankfully I had a few bits at work that nobody would miss so I started to work out what I need to buy and what I already had. The parts I could find around the lab came to a saving of around £0.75. I could go through all the parts lists, sort out the bits I already had which would take some considerable time or I could just post the parts list from the Wiki (yes I did find that bit in there). I gave in and just ordered the pars and hoped the wife wouldn’t see the additional £100+ bill on the card.

I’m in the lucky position that I work with surface mount components every day. Many of the parts on the boards are larger surface mount or even thorough hole so it was relatively easy for me to do the assembly. If you’ve not done surface mount before DO watch the tutorial on how to solder surface mount chips (it’s in the wiki :o) ) or just search YouTube for tutorials on the subject. It’s not too difficult when you get the hang of it. Just be sure to have plenty of solder wick and patience to hand. When I was first shown the chap took no more than 2 seconds to solder down a 20 pin device. When I first tried it took me more like 5 minutes and plenty of de-soldering each poor attempt.

So now I have all the boards built, I’ve acquired a box, stripped out all the bits that were in the box (anyone want some RF down converter modules, S-band to 70cm. Custom made with no instructions) and started to bolt it all together. As I had a bunch of RF relays around I decided to use them for the RF switching. The switching and the 4 band decode aren’t really needed. I’d bought and built the 4 band decode before I worked out what it dose so added the relays just to be a bit posh.

For information, the Portsdown outputs at 4 different bands that you can select. The 4 band select and RF switching allows you to switch the output to different antennas. If you’re agile or unlikely to change band then it’s easy enough to do this manually. Just unplug one antenna and plug in a different one when you change band. No big deal really unless you get it wrong and are running high power when it could get messy.

Let’s turn it on. What power do I need? Raspberry Pi 5.1v, well that’s a bit tough but hey, get a nice big 5.1 PSU and I’m done, nope. Switch board, 3.3v , LO filter and modulator, around 7v, could be 12v but the linear regs might get a bit warm, relays 12v. Back to ebay and get 3 PSU’s like the MiniTiouner uses for a couple of quid each. When they eventually turn up stick them on some Vero board I had and, all ready.

Test the relay switching, Hmm. It didn’t work. The first relay didn’t switch, check the 4 band board and the output doesn’t work. Duff device from the get-go I guess, move the relay to a different output. That doesn’t work either. Check the third output with a meter, seems OK, move the relay to that one. Nothing, the output is dead. Check relay, oops it has a protection diode on it and it’s the wrong way around. OK, a new set of switches on order and do away with the switching for now.

So now I have a proper working transmitter that gives a very nice image on my MiniTiouner. I’m there! Errr… nope not yet.

10mW is never going to get to the repeater. OK, what RF amps do I have? -10mW in 4W out, that’s not going to cut it I need to run at ½ max power at most to avoid non-linearities so 2W will not make it I’m sure and I’d be over twice the max input power.

100W amp, that will do the job well it would if it didn’t need a 5W+ drive. My 10mw gives around ¼ output if that. It’s difficult to read on a 5watt bird meter.

What the hell, try the 4Watt one as I know it pokes out some signal. Nope, can’t get into the repeater. Try the 100W amp in case I was too distorted, nope not enough power. Try both together! Yea around 50W of power! I get in on 23cm at 15W so 50W at 70cm should get me there easily, nope. Repeater beeps at me but won’t see any signal. Maybe too distorted, so I borrow a variable attenuator, tweak it so the 4W amp is outputting around 2w, the 100W amp now puts out about 20W so this should be good! GB3HV says ‘beep beep BEEEP’ . OK, Lets see if anyone on BATC would like to buy a Portsdown. I’m obviously not able to get this working quite right. I can’t justify £500 on a new amp so I guess it’s time to give up after a year of building. It’s Monday night and I’m off to bed.

Tuesday evening, I might as well stay up late for the weekly GB3HV natter. I’m normally in bed by 9pm which is when the natter starts. Tonight I might as well have a late night and see if anyone has any ideas.

A quick chat and Noel G8GTZ suggest I give it a go and they will see what seems to be happening. “Err, are you tx-ing Mpeg4? The repeater only takes Mpeg2?” Says Noel.

How would I know? I just built it I don’t even know what the difference is. I’ve just set it to the test pattern.

Noel tweaks an online monitor and I see my picture at a distance for the first time ever! “yep, that’s Mpeg4” say’s Noel, “Lets get Dave, G8CKQ on line as he knows this stuff better than anyone”.

Dave pops up, is told the problem and suggests I press the far left button as that’s the only one that does Mpeg2 he says.

Within seconds I’m getting a perfect image into GB3HV with the Raspberry Pi camera.!

Finally, I’m there with a genuine working system.

Now, how do I connect a normal camera and audio? Ah, well, I just need another couple of dongles, one for video and one for audio. Back to Ebay and the BATC shop it is then.

Note, Dave is working on getting the video and audio from a single dongle as I type, 7/7/2017, so I’m going to wait a bit and see where that goes.

The morals of this tale

1. Always check how long an article is before starting to read it. If you’ve got this far then it’s probably time for bed now.

2. RTFM before you start. It could save you more expense that you planed for and a lot of time placing multiple orders when you could have got it all at once.

3. Don’t give up. I was right on the edge when it all fell into place with the kind assistance from a couple of knowledgeable people.

Contents ^

Gave a good Digital-ATV Presentation to JPL Ham Club in Pasadena

By Ken W6HHC and Robbie KB6CJZ

Reproduced from the Orange County Amateur Radio Club newsletter. www.W6ZE.org

On July 14, Robbie KB6CJZ and Ken W6HHC provided a one-hour slide show with a show-and-tell session about the current advances in Digital-ATV to the JPL ARC in Pasadena, CA. Can you imagine, these hams are all part of the “flight communications systems” section of JPL for space probes and Mars-landers, etc….so they really know communications. So, I really had to “be on my toes” when talking about capabilities of RF communications used by DATV. For example: they completely understand that when the antenna gain gets impacted…you could narrow the RF bandwidth (slow down the data rate) to compensate for the loss of antenna gain. So, when I talked about improved DATV S/N reception using Reduced Bandwidth DATV (RB-DATV)…every head was nodding. Josh KB3UUS of JPL explained to us that some signals are as weak as around -160 dBm and JPL sometimes reduces the RF bandwidth down to 10 KHz to receive the incoming data stream from space. Josh went on to explain that the “closer” spacecraft at Mars and Jupiter are usually around -130 to -140 dBm.

The presentation covers DATV protocols, digital modulation technologies, current exciter equipment, MiniTiouner analyzer, and useful URLs

They said they learned a lot about concepts of DVB-S and DVB-T protocols and the overview of DATV exciters (including the Portsdown Project) and MiniTioune analyzer and appreciated the list of URLs to get started in DATV. Hopefully, we stirred up some interest in DATV at JPL ARC. The presentation PowerPoint and PDF files are available for download at www.W6ZE.org/DATV/

Robbie and I received a two-hour private tour of the Mission Control Center room and the JPL Museum which has models of all their space vehicles (some full size). Very cool…and we did not have to elbow through any overwhelming crowds of competing visitors that occurs during a JPL Open House event.

MORSE CODE LIVES ON MARS

An interesting artifact that we saw was: the tires of the Mars Rovers in the museum have an imbedded Morse-code pattern with the letters “J – P – L”.

The full-size Mars Rover model exhibits Morse Code for J – P – L

embedded on tires

The purpose of the embedded tire patterns is to allow JPL to visually inspect the tire marks in the Martian dust with the Rover cameras and look for a mal-functioning wheel…perhaps “dragging along” instead of correctly rotating.

MISSION CONTRL CENTER

The Mission Control Center at JPL allows the Center to collect data from all of their spacecraft simultaneously if required.

The view from the visitors-gallery allows seeing all the displays at

the Mission Control Center

JPL gathers data and can send “control commands” to any of the spacecraft that are active, using radio telescopes at three locations on Earth. The clusters of radio-telescopes for the Deep Space Network are located at Goldstone, CA and Madrid, Spain and Canberra, Australia are all separated by 120 degrees of longitude so that tjey can be pointed to any spacecraft location at any time of the day. A NASA web URL to show the current activities of these radio telescopes can be found at: https://eyes.nasa.gov/dsn/dsn.html

Contact Info

The authors may be contacted at W6HHC@ARRL.net and KB6CJZ@ARRL.net

Contents ^

MP3 Sound Module Review & Application Notes

By Mike Stevens G7GTN

I was looking at simple options to allow adding either speech or simple sound clips to an ATV project and thought the £1.82 module I choose might be of some interest to others.

I guess many of us have seen the types where your clip to be played is stored on an SD memory card or indeed the types that flash memory is programmed using a dedicated external USB hardware device. The specific one I choose is different in that the module is connected by Micro USB to your Windows PC and a built in application then launches to allow you to upload your required sound clips. These are saved in the on-board flash memory with playback options being accessed via 9600 baud serial commands.

Module Hardware

The module measures just 20mm X 17mm and is self-contained requiring just a +5V supply and a means of triggering the file to be played back (more on this later) connections are made via male pin headers enabling this to fit very nicely on some stripboard. The heart of this module is the JQ6500 MP3 decoder chip alongside an SPI Flash memory (16Mbit Capacity) to store the actual clips to be played. The output is either an 8Ω speaker or via a pair of DAC pins for driving an external amplifier of your own choice. Power supply requirements are from 3.5V up to a maximum allowed voltage of 5V. A caution on the modules RX pin not being 5V Tolerant and hence requiring a 1K series resistor if you wish to drive this from standard 5V micro controllers directly. Any 3V3 TTL logic level processor devices are totally safe and hence do not require the use of this additional protection resistor.

Uploading your own audio clips

To prepare the module with your required clips, once plugged in to your USB socket the device enumerates as a CD device. Once clicked you will be able to double click on the up-loader executable file to launch the software to allow uploading your required clips to the 16Mbit flash memory device. As depicted the software screens are all displayed in Chinese but selecting the second tab allows file uploads to be made. You can select multiple files or add them individually one at a time.

Control Methods

The playback and certain other limited functions of the module can be controlled via standard pushbuttons connected between pins K1 & K5 with the other end going to ground. This provides a somewhat limited control mechanism and we would probably prefer a more software controlled method using the RX and optionally the TX pin to communicate directly under our own control.

Ardunio Test Code

The commands are sent as a series of 3 hexadecimal bytes the most useful are summarised for reference in Table 1 an already written library makes control far easier as we can then just call functions where required in our own code. One such library is written by James Sleeman and can be downloaded from https://github.com/sleemanj/JQ6500_Serial Once installed in the IDE we are ready to do some quick tests with audio playback. A zip file called MP3TEST is available that contains the very simplest test code along with two MP3 Audio test tones of 1KHz and 440KHz. The IDE serial monitor is used to select which clip to play from a small displayed menu. The library talks to the MP3 module at 9600 baud-rate using software serial. The RX pin on the Ardunio remained unconnected as I was not interested in any status information coming back since this was only a quick test setup. However there are some commands that might prove of value for polling the module in your own custom applications.

ESP8266 Test Code

With our ESP8266 micro modules we can now also dispense with the serial resistor on the RX Pin since the logic levels are all driven at 3V3. Since we have the capacity to create web interfaces a simple page was implemented. For this you need to enter your routers SSID & also Password in the top section of code, once uploaded your module will be at the IP address that you have specified. In your standard web browser enter this address pre-fixed by the normal HTTP header string to access the web control page.

Serial commands – Hexadecimal Format

As depicted in Table 1 (not all shown) the commands are sent as a series of hexadecimal control bytes.

So we can quickly see that it is far easier for us to use more English like function names that the downloadable library provides us with such as :- mp3.setVolume(30)

Conclusion

If you require a simple and ultimately cheap investment for any sound playback solution this might be worth further exploring. Some project ideas could include Morse or even speech playback on your ATV Repeater system, or for home use TV Test tone generators – other applications are over to you.

Contents ^

A Simple Home Constructes Weather Station

By John Hudson - G3RFL

Until recently I was the proud owner of a simple electronic home weather station, that I admit was an impulse buy from Maplins, the home electronic store. I was rather attached to it and a little sad when it stopped working. Fortunately a visit to the store and some helpful advice from the manager, “bring it in doors when we have bad weather”, I can now see how he got to be the manager.

OK time to put my engineering hat on and see what can be done about a weather station that can actually survive the weather that it indicates. The first thing was to research the outside parts and I was pleasantly surprised at the cost of the required sensors.

The N25 FR rainfall indicator for less than £5

This is a standalone rain gauge. Rain collects in a self-tipping tray that empties when it fills with 0.01 inch of water. Each time it empties, a sensor sends a signal to your motherboard, so if it tips 100 times, it’s measured an inch of rain. The measured rainwater drains out of the bottom of the gauge and falls to the ground. Bolt it to the pole opposite the housing and with an unobstructed view of the sky. Debris can catch loosely swinging wires and tear them down in bad weather. So run the cable along the rain gauge mount, along the opposite housing mount, into the housing, and all the way to the motherboard.

Wind Direction Sensor N96FY/N96GY for less than £10

This works by rotating a magnet over a circle of eight read switches. One or at best two can be made at once depending on the position of the magnet. The switches control a resistor ladder that creates an analogue voltage dependent on wind direction.

Anemometer for N25FR £2.49

There are three types of anemometer worth buying: three-cup, propeller, and sonic. Wind spins the cups or propeller to measure wind speed. The propeller anemometer is usually more precise than the cup anemometer. Sonic types are less likely to break or freeze because they have no moving parts, but most cost more.

Not the most difficult task to deploy this kit up the mast and deploy the cables back into the nice warm shack and think about how to interface them to a display screen.

The circuit diagram

SW1 to SW8 are located in the weather vane head and provide the wind direction. They are simple reed switches and are used to change the value of resistors in the top of a potential divider ladder network. That together with R11 change the potential on the analogue input (pin2) of IC1, so a voltage proportional to the wind direction is delivered to pin 2, the analogue input of IC1. The software takes multiple samples and averages them out as the wind vane does tend to bob about.

SW9 is the micro switch in the rain detector head and every time the tray fills beyond its tipping point, the switch closes and the tray empties. This delivers pulses to the port pin 3 on ICI. The more frequent the pulses the heavier the rain fall. If you want to log monthly rainfall you can count the pulses over a 4 week period. The rocker had to have its reed switch placed on the other side of the PCB so it gave a pulse each time it rocked. In snow conditions this stops working, frozen up, but at least we know it’s not raining!

SW10 is actually two switches in the anemometer head. These deliver pulses every time the wind cups revolve, so again the more frequent the pulses, the faster the wind is blowing.

IC1 is programmed to decode all this information and the code is on the CQ-DATV website. IC1 interprets all the data and communicates it via the I^2C bus to the LCD readout. Simple really, all the sensitive stuff is indoors and the clever stuff is all done by software.

The business end of my weather station, indoors and out of the way of any weather problems.

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GB3FT - A 24cm Digital ATV Repeater for the Fylde Coast

By Tim Forrester - G4WIM

Background history

I’ve had an interest in ATV since the late 60’s when a local amateur (Brian Seedle G3UIT) showed me his entirely home brew station for 70cm – he even built his own solid state camera (except for the vidicon tube), quite an achievement.

I was originally licensed as G8GIW in 1972 but it wasn’t until the late 80’s that my interest in ATV was rekindled. Ultimately resulting in the building of GB3MV during the early 90’s. I understand it is still in operation in the Northampton area and using the original Sinclair Spectrum caption generator.

ATV has moved on in leaps and bounds since those early analogue days and now due to the availability of digital hardware and the efforts of the BATC group as a whole it is much easier to assemble a working ATV station.

The following pages offer a brief summary of the technical side of GB3FT and future plans.

GB3FT Status and Coverage

The license approval for GB3FT is pending with no indication as to when it might be approved, however the hardware for GB3FT is being tested under clause 10 personal beacon at the location of G3WGU.

Steve G3WGU has kindly agreed to be repeater keeper and to have GB3FT installed at his QTH which happens to be one of the highest points on the relatively flat Fylde coast.

The repeater is located in his attic with a very short run of low loss coax to the chimney mounted Alford slot.

For license reasons, Steve has final manual override on transmitter operation.

Initial tests indicate coverage is very similar to that predicted, see coverage map below.

GB3FT Hardware

The GB3FT transmitter sat on top of its receiver and command section

The front panel has various controls and indicators to aid operation and maintenance.

Given it’s eventual location, keeping the PA cool is essential hence the over size heat sink and fan. The heat-sink is 300mm x 300mm x 35mm.

Another view from the top showing heat sink and cooling fan for the power amplifier.

Rear View – showing connections for the command receiver

GB3FT in operation showing my callsign signal being relayed

The following paragraphs go into some detail as to how the repeater was built. Below is a simplified block diagram.

The hardware is relatively straight forward with contributions from a number of local (and not so local) amateurs, as per the block diagram.

There is also a command receiver listening on 144.750MHz. See the GB3FT qrz.com page as to how this is used.

Transmitter Section

Below is a picture of the transmit section with the PA and heat sink removed.

It shows the internals of the transmitter. Lower right is the DTX1 with the 1315MHz filter just showing above it and the Raspberry Pi Zero next to it for test card generation.

The duplexer is on the left – it has an insertion loss of 0.37dB at 1315MHz and and 0.7dB at 1249MHz. Thanks Mark GM4ISM for providing this key item free of charge.

The transmitter runs at 5 watts output after duplexer loss and has a reasonably clean spectrum as show below.

Receiver and Command Section

The picture below shows the internals of the receiver die cast box.

There is the PCB from a Comag SL30/12 digital rx on the right and analogue receiver from G3ZGZ on the left. In the middle is a small veroboard circuit containing the lock detection circuits and signal routing.

The 4 pole inter-digital filter and signal amplifier are attached to the lid of the box.

The signal from the LNA connects to the inter-digital filter at top right.

The rotary switch at bottom middle selects system off, automatic relay, force digital mode, force analogue mode or force auxiliary input. Normally it would be left in automatic relay mode.

A tight squeeze but everything fits – just!

The digital receiver produces a D5 picture down to -102dBm, whereas the analogue is a P3 at -100dBm.

These figures could be improved a little bit as could the antenna gain by moving from an Alford slot to a slotted wave guide – something to be considered for the future.

There is no detectable receiver de-sense when the transmitter is in operation.

Conclusion

The hope is that GB3FT will foster more ATV activity generally on Fylde coast and surrounding areas and ultimately provide a link to / from GB3FY which is on 10GHz but whose signal is blocked to the South by the higher ground where GB3FT will be located.

There is also a plan to stream GB3FT into the BATC website.

All we need now is formal license approval – but in the meantime clause 10 is a good second.

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DATV-Express Project - June update report

By Ken W6HHC

Charles G4GUO has alpha-released v1.25 of the DATV-Express-for-Windows code. This new version cleans up a few problems:

- Should work with non English versions of Windows (such as Japan, etc). This mainly applies to users of languages other than English and French. This change should now allow you to select video capture formats.

- Not all possible FEC rates are permitted for each type of modulation. The GUI had been trying to set illegal values (or no values at all).

G4GUO has not tested this software so is looking for BETA testers to do some testing. When the Project Team gets some feedback from BETA testers we will THEN put the new v1.25 code on the normal http://www.DATV-Express.com DOWNLOADS page. In the meantime you can download the alpha code from: https://www.dropbox.com/s/hjsbblik5gpgjhz/setup_datv_express_transmitter1.25.zip?dl=0

Finally, the NOTES file (aka README) for v1.25 is available on the normal http://www.DATV-Express.com DOWNLOADS page.

It is delightful to see “jiang wei aka @ jocover” start working with the DATV-Express-for-Windows software code and begin porting it to the LimeSDR hardware board. In June, Charles G4GUO had released the source code for the project Windows App on github at https://github.com/G4GUO/DatvExpressTransmitter

Charles has dubbed this DATV-Express and Lime Windows app as “LimeExpress”. This software for the LimeSDR is early in the porting effort and only works currently in the DVB-S2 protocol. G4GUO explains that the good news is that jiang wei has created a framework in his LimeSDR software efforts to allow others to start filling in the missing functions code. You can learn more and download the LimeExpress code .exe at: https://discourse.myriadrf.org/t/windows-based-dvb-s-s2-t-transmitter-for-limesdr/1348

Even more good news is that Evariste F5OEO has started to look at the LimeExpress code and has made a few tweaks to the code for the LimeSDR hardware board. This software is unsupported by the DATV-Express team, but it was very nice to see other people taking an interest in the project.

Art WA8RMC has been hacking away at cheaper/smaller version of the MiniTioune hardware board. Ken W6HHC calls this (with tongue-in-cheek) a “cheap American knockoff” of the current European MiniTiouner Serit-tuner board. Art has estimated that he can assemble-test-and-sell this design for less than US$100.

Only a “hardware hacker” could call this prototype beautiful…but, it WORKS!

Art also reports good inventory on the DATV-Express boards.

Charles G4GUO has been day-dreaming about a mini-project to extend the frequency range of the basic DATV-Express hardware. Currently this concept board (tentatively called the “Express-frequency-extender”) would attach to the RF output of the DATV-Express to transmit on 50 MHz, 3.4 GHz, and 5.8 GHz ham bands. The concept would also provide a receiver frequency converter to take the output of your 3.4 GHz or 5.8 GHz antenna external preamp and down-convert to perhaps a 430 MHz or 1200 GHz receiver.

A classic “back of envelope” sketch of possible Express-frequency-extender concept board Block Diagram

The only real problem is determining if “there are enough interested hams to make this project worthwhile?” Please provide some feedback (via this forum or by e-mail) to Charles if you would be interested in this frequency-extender accessory for the DATV-Express board?

Future DATV-Express Project Reports are still expected to be quite short for the rest of 2017.

“Project speed set to back-burner” …. de Ken W6HHC

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The popular Video sync generator; The new ‘Syncsmurf’!

By David PE1MUD and Tjalling PE1RQM

Article updated: May 2, 2017 (https://www.pe1rqm.nl/syncsmurf2/)

Introduction

Since the end of 2011, a particular circuit has been very popular among Amateur Television (ATV) amateurs: the “video sync generator” designed by Hans PA0JBB, or the “video squelch killer” or the “video enhancer” etc. The circuit has in the Popularly quite a few names were received.

This was a circuit designed to bypass the annoying ‘no-signal’ notification and noise suppression on LCD monitors. Because for ATV amateurs it is especially important to be able to look deep into the noise even with weak signals. Old-fashioned CRT monitors (display tubes) do not suffer from this. But a particularly pleasant occurrence is also that the image of weak signals is more stable with the combination of Video sync generator and CRT monitor. So for those users, the circuit is useful (hence the name “video enhancer”).

Video Sync Generator Version 1

We are now almost 5 years old and the original design has undergone a lot of modifications. This became a nice collaboration between a number of people, including myself. They were extensively described on this page of this site.

Syncsmurf 1.0

SMD versions also appeared last year. David PE1MUD has also been busy with it and called his version the ‘Syncsmurf 1.0’. This first version was not only smaller, but already had all available modifications on board and had a more efficient voltage regulator. The power consumption decreased from about 90mA (at 12V) to 50mA (at 7 to 15V) using a switched-mode voltage regulator. This was relevant for portable ATV use (batteries).

David and I have tested a lot and exchanged ideas. David is good at designing small electronics, so version 1 of the Syncsmurf had to be better! There was still something to be found on version 1. Something Hans PA0JBB himself had already described in his original article. We found the video amplifier “just good enough for normal use” (read: could be better), the thick electrics for the AC coupling were annoying, which also caused a slow start of the circuit. The control range of the 5MHz VCO for the PLL in the SAA1101 sync generator (to synchronize with the incoming video) was too limited. This could not cover all the different video equipment used by our amateurs. Therefore, it could happen that the video was still moving.

In September 2016, version 2 of Davids PE1MUD’s SMD version was announced; Syncsmurf 2.0! And he is also offered for sale (on reservation). See bottom of this page.

Syncsmurf2

The Syncsmurf2 has been improved on many points:

- PCB is even smaller than Syncsmurf 1.0, namely 41 x 46mm. This is even less than 1/8 of the original though-hole euro card version! And the circuit is also smaller platter by smaller elco’s. The circuit could be built in size in many LCD monitors!

- The video amplifier has now been replaced for a MAX4090 IC. David told us: “This complies with frequency broadcasting standards, SNR, groupdelay, diff gain and phase and has 80dB suppression of common mode rejection.” The latter seems to be quite bad at the original video amplifier.

- The new video amplifier does not require any major elecs. This makes the circuit smaller and platter. Another advantage is the faster start time of the new version, due to the smaller elco’s.

- The “capture range” of the incoming video, to which the SAA1101 can synchronize, is no longer settled with a trimmer. This is now done with an additional varicap with external meter. This ensures that most available ‘amateur’ video sources will be covered by this new external arrangement. Yet there are sources that differ too strongly, not everything is catchable.

- The previous point is also immediately the manual function. Actually a kind of hybrid between car and manual. Put the video virtually still with the potmeter and the PLL then locks and quiet the video. It is still possible to disconnect the PLL output with a switch and connect the 0-5V output of the potentiometer to this second varicap. Then you have a full manual function and a slightly bigger catch range.

- The video stays stable when a signal contains a lot of noise. Spikes in the Varicap control, caused by noise, are now cut off with a zener diode.

- The current version of version 2.0 has been reduced from 50 to 30 mA. With the through-hole version it was more than 80mA. So a big win, ideal for portable ATV!

- The sync generator is easy to switch off with a single switch. The video amplifier is then directly disconnected with the original sync pulses. This can be seen by you if it is in bypass of the circuit. The circuit is therefore in a low-power mode.

- The colour burst’s kernel does not need to be sorted out.

- The 624/625 jumper is now easy to connect as an external switch. This prevents jumping of an image line during synchronization.

Technical data

(Package owner owners, download the PDF under the partlist, including all comments on supplied items and other items. There is also a connection schedule available)

This version is configured for the PAL standard.

Schedule Syncsmurf 2.0

Syncsmurf 2.0 PCB top

Syncsmurf PCB bottom

Partlist, Note: Behind BB199 stands as device BB141. That’s not true, it’s just a BB199.

Documentation for the builders

Note that PCBs 2.0 and 2.1 have R14 and R21 interchanged on the silkscreen. Stupid mistake, sorry. Please check the schedule and change these resistors. The circuit will work, but less well. After my holiday, I will send an email containing this change.

Syncsmurf 2.0 package description - Syncsmurf-2.0-beschrijving-voor-bij-bouwpakket.pdf (https://www.pe1rqm.nl/download/Syncsmurf-2.0-beschrijving-voor-bij-bouwpakket.pdf) Please note that this file is in Dutch.

Placement hard to read parts:

Pen 1 of the MAX4090-EUT-T may be somewhat unclear. If possible, make the impression more visible with side lights (sometimes works better than straight from above) and a peek. The text ABOX should be placed as follows:

The BB199 is very small. This component looks like this after a big increase:

K = Cathode, A = Anode

Two more pictures of built-in copies:

Interested?

We are going to offer this circuit for sale on this site. David PE1MUD takes care of the production and support and I (Tjalling PE1RQM) take care of the distribution.

The price for the PCB only amounts to €9.00 (excl. Shipping). The price for a building kit ( excluding external potometers, switches, housing and shipping) will be €50, -. Completely built and tested costs €90, - and is available only on request ( excluding external potometers, switches, housing and shipment).

Shipping costs €3.00 for PCBs and building kits, €5,00 for built-in copies. For shipments outside of the Netherlands we will have to calculate shipping costs.

Please note, there is a delay in delivery due to some errors in the delivery of the components. The building kits are available in a few weeks, the PCBs are a little earlier.

Warning

Keep in mind that some components are difficult to find in small quantities. Therefore consider the building kit. Because we buy properly, we can not sell any items separately. The coil, the power supply and the video lamp are something specific. The SAA1101T, MAX4090, BB199 are obsolete, so we put out of NOS (New Old Stock) sources. That’s once! The components are mainly in the small 0805 SMD format ! There is some experience and good eyes needed to solder it well.

The BB199 may be hard to get. We are investigating some alternatives. For example, the BB198 or the BB205. The results are not known yet, so if you’ve tried that, we’d love to hear! Our building kits will still have the BB199 for the first time.

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Contents ^

Information

About this eBook

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Many articles include programming code or configuration examples. that will 'wrap' on smaller displays.  To optimise the presentation of these elements, view the eBook in single-column, landscape mode and adjust the font size to the smallest setting.

External links

If you have an eBook reader that does not have WiFi then you will not be able to use the hyper-links in this publication.

If you have an eBook reader that has WiFi then you will be able too providing you are in a WiFi zone.

But if you have a Kindle 3G then yes, but only to Amazon, and there is not a lot of ATV material on their site.

Smart phone or tablet reading apps are ok providing that you have a WiFi or 3G/4G data connection.

Note: These links will fire up your devices browser and if you are using 3G/4G then you will incur data usages charges.

The Internet is a living thing that is constantly evolving. Whilst all external links are checked at the date of publication, they may not be valid in the future.

Legal Niceties (the small print)

E&OE. Whilst every care is taken in the production of this publication, dotMOBI accepts no legal responsibility for the advice, data and opinions expressed. dotMOBI neither endorses nor is it responsible for the content of advertisements or the activities of those advertisers. No guarantee of accuracy is implied or given for the material herein. dotMOBI expressly disclaims all liability to any person in respect of anything and in respect of the consequences of anything done or omitted to be done wholly or partly in reliance upon the whole or any part of this publication.

As the regulations for the operation of radio frequency equipment vary in different countries, readers are advised to check that building or operating any piece of equipment described in dotMOBI will not contravene the rules that apply in their own country.

All copyrights and trademarks mentioned in this publication are acknowledged and no infringement of the intellectual copyright of others is intended.

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The articles contained in this publication remain the copyright of their respective authors and NOT dotMOBI. Any reproduction of such articles must be approved by the author of that article.

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