Contents

Cover

Production Team

DATV News

World DATV Party goes ahead

The 2014 ARRL/TAPR DCC

Known DATV DX Records

Editorial

Calling all BATC members

What is the solution?

The New Team

How will it function?

MAX7456 OSD Computer USB Controlled

Computer Control Application

Serial Terminal Control

Two Geostationary Amateur Radio Transponders on Es’hail 2

Es'hail-2 coverage area

Amateur Television Quarterly

Digital Repeater TV DVB-S 1200 MHz 10 GHz

Receiving Antennas 1200 MHz

Coaxial Coupler

The Bandpass Filter.

The Receiver Module

The 480 MHz Filter

The 480 MHz amplification chain

External Parts

The Mixer

The 10 GHz DRO oscillator

The 10 GHz filter cavity

The Power Amplifier

The Magic T

The construction of the transmit antennas at 10 GHz (Horn)

MAX7456 OSD PC RS232 Serial Programming Interface

Circuit description

Practical Implementation

DATV-Express Project - July update report

TV Amateur

Information

External links

Legal Niceties (the small print)

Copyright

Notice to Contributors

Coming up

CQ-DATV 15 Production Team

- Terry Mowles - VK5TM

- Trevor Brown - G8CJS

- Ian Pawson - G8IQU

- John Hudson - G3RFL

- Mike Stevens - G7GTN

- Fabrizio Siena - JN53RH

- Ken Konechy - W6HHC

- Dave Kenward - G8AJN

- Richard Carden - VK4XRL

- Klaus Kramer - DL4KCK

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.

DATV News

World DATV Party goes ahead

Despite software issues the World DATV Party will go ahead as scheduled.

While most activity in this annual global event is based around Amateur Radio ATV frequencies, Skype is used for Interstate and International connections.

However Skype is currently grandfathering out older versions and the new version does not support import video from USB Dongles such as EzCap. These are used to take the output video as received from the ATV Repeater and send it to the remote anchor station.

Fortunately Peter VK3BFG has found a temporary work around, but it will be depend on the administrators of Skype and their timetable.

The event is on and will take place on Friday August 29th and Saturday August 30th (Melbourne Time) Friday night will be locals and interstate and should start around 8pm. We will make contact with the Brisbane DATV Repeater VK4RMG and also the new DATV Repeater, VK5RDC in Port Pirie.

Saturday will commence at 10am to pick up WR8ATV in Columbus Ohio. This repeater is located on the top of a tall building in downtown Columbus. All antennas are within 15 metres of their corresponding transmitters. WR8ATV has 5 outputs with one on 1268 Mhz DVB-S; it has 4 inputs.

By contrast, VK3RTV has 3 inputs (one U/S at the moment) and two multiplexed outputs. The local anchor in Colombus will be Art WR8RMC. Some may recognise Art as one of the developers of the very innovative DATV Express.

Around lunch time the event moves to the W6ATN network in southern California.

There are nine linked repeaters based around a hub on Santiago Peak. Don, KE6BXT will be the local anchor.

Later in the evening we expect to move to GB3HV and make some contacts into the UK. GB3HV has a Skype input and contacts can be made directly.

There are a number of Melbourne based stations who are preparing for the event. Melbourne always puts on entertaining contacts with lots of show and tell. This year the new WIA supported ATV installation at the Eastern and Mountain Districts Radio Club will be active also.

If you are unable to receive any of these repeaters direct, you can watch the activity on the BATC streaming site for all involved. Remember the dates, August 29th and August 30th.

Jim Linton VK3PC

The 2014 ARRL/TAPR DCC

The 2014 ARRL/TAPR DCC will be on Friday, September 5th through Sunday, September 7th at the Austin Marriott South in Austin, Texas.

The DCC has two days of technical forums on Friday and Saturday and a concurrent introductory forum on Saturday.

On Saturday night, the banquet will feature an interesting speaker and the Sunday morning seminar will be "Introduction to SoC FPGA Programming for Mixed Signal Systems" by Chris Testa, KD2BMH.

There will be free tables in the demo room to demonstrate projects and vendors to demonstrate products.

Time is running out, so those interested in attending should register for the DCC and make hotel reservations ASAP.

More DCC information is available at: www.tapr.org/dcc

Hello, Since this summer we are testing with Evariste F5OEO DATV transmission at very low Symbol RAte down to 250 kS / s.

It works very well with the image that is not too ashamed to face our old VHS recordings.

You can see a sample of what I get here: http://www.vivadatv.org/viewtopic.php?f=72&t=332

It's a start, but it shows that narrowband DATV is also a solution in sight and we can explore this area on our bands.

We should be able to get off SR 100KS / s. These widths as narrow bands induced should concern DX men I guess.

73 to all. Jean Pierre F6DZP

Known DATV DX Records

Editorial

Welcome to CQ-DATV 15

Lots Happening on the DATV scene with a major article from our new recruit Fabrizio Bianchi, IW5BDJ in Siena Italy. CQ-DATV is really evolving into a world ATV magazine, welcome to CQ-DATV Fabrizio, We hope to see more contributions from you in the future.

Mike G7GTN has developed his OSD project to the next level with USB control. He also provides a simple RS232 interface for those that prefer this option, in a separate article.

Qatar's Es'hail 2 satellite also has interesting connotations for our hobby, geostationary communications that could link amateurs from Brazil to India.

With the number of new satellites launched or scheduled for launch in the near future, this is an exciting time for amateur satellite communications and experimentation.

In the July DATV Express update report, Charles G4GUO has received his ODROID U3 ARM-based micro-PC and reports on it's performance.

Trevor has returned from his heart bypass operation and taken the time to explain what happened with the BATC committee.

CQ-DATV shares a lot of members with BATC. Please try to attend BATC BGM on the 7th September to support our rescue plan. The club has been around since 1949 and is a pillar of support for ATV.

Let's put a new management team in place that will maintain and lead BATC into the future. I know you may not have all had plans to attend the BGM, could these be revised as your support is vital to stop the new constitution being steam rollered through in the first ever BATC BGM.

You have seen us all in action, you know we can deliver, now we need your support for our Plan on 7th of September.

CQ-DATV 16 is being worked on as we speak, but you will see from Trevor's plan we would like to merge CQ-DATV and CQ-TV. The new magazine will remain as a monthly electronic magazine. ATV is fast moving and we need to keep up. CQ-TV has only ever managed three issues a year under the present team, this is not enough, particularly if you are paying for four paper copies per year.

Please sit back and enjoy CQ-DATV 15.

MAX7456 OSD Computer USB Controlled

Mike G7GTN

The MAX7456 OSD Modules that we have been using and configuring in different ways can also be easily controlled via USB if you ever had such a requirement to do so. I feature a simple eBay USB interface module and some custom cross platform desktop software. Total cost should be under £1.00 ($1.67 approx) if you use one of the Prolific (PL-2303) chip based Serial to TTL modules.

We need to connect the TX output pin of our USB converter to the RX input pin on our OSD Module also connect the TX pin on the OSD to the RX Pin on the USB. Simply put is just a crossover connection to allow correct communications between the two. We next have to place the control software on the OSD module using our FTDI USB Breakout. The file required is from the OSDUSB.ZIP downloadable from the usual CQ-DATV Magazine additional material location.

The Desktop Application is but a very simple example of serial communications, which you can of course update with things you would like available. This is written using the free software development package called B4J which is available from http://www.basic4ppc.com/android/b4j.html

The compiler allows you to develop cross platform applications which are compiled down to native Java code which then runs on top of the Oracle Java Runtime Environment (JRE) depending on what software you have previously run on your machine will determine if this runtime is already installed. If not you need to visit the Oracle website and download & install the following package http://www.oracle.com/technetwork/java/javase/downloads/jre7-downloads-1880261.html

The actual IDE only runs under the Windows operating system. So to further develop the source code provided you will require access to a machine running Windows XP or above until you have completed your modifications and created the final compiled Java runtime file.

My USB Module happened to be based on the PL-2303 Prolific Semiconductors device, but really this is not relevant as long as you can obtain an operating system driver for the chipset that your module is using. I have also tested this with the much more common FTDI FT232RL based modules.

Computer Control Application

The control utility consists of three files, the first being the executable code. This is called OSDUSB.JAR this is launched by double clicking on it. The other two files are firstly a basic HTML help file and lastly a settings file to store and also restore the Brightness White Level of video captions. The source is fully commented with explanations of other files you will need to download to work further on this sample project. This is only required if you wish to expand this code with your own personal modifications.

Serial Terminal Control

if you also wish to just control the OSD module from your favourite Serial Terminal instead of this application then the settings you will need are Baud rate 9600, 8 data bits, No parity, Stop bits 1

The commands shown in FIGURE1 are understood by the control code as presented.

I hope you will also have some fun with these modules and the possibility that computer control might bring to your Amateur Television station operating.

Two Geostationary Amateur Radio Transponders on Es’hail 2

Qatar’s Es’hail 2 satellite will provide the first amateur radio geostationary communications that could link amateurs from Brazil to India. The satellite is expected to launch by the end of 2016 and will be positioned at 25.5 degrees East.

AMSAT-DL President Peter Guelzow DB2OS at the Qatar National Day Station A71QND

AMSAT-DL President, Peter Guelzow DB2OS, has provided the following information:

Es’HailSat-2 will carry two geostationary “Phase 4” amateur radio transponders !!

As a result of a concept proposed by the Qatar Amateur Radio Society, Es’ Hailsat, the Qatar Satellite Company, have announced that their new, geostationary, Es’HailSat-2 communications spacecraft will provide transponders for use by radio amateurs. The spacecraft is expected to be ready for launch by the end of 2016.

Es’HailSat-2 will provide a 250 kHz linear transponder intended for conventional analogue operations in addition to another transponder which will have an 8 MHz bandwidth. The latter transponder is intended for experimental digital modulation schemes and DVB amateur television.

Es'hail-2 coverage area

Precise uplink and downlink frequencies remain to be finalized but the uplinks will be in the 2.400-2.450 GHz and the downlinks in the 10.450-10.500 GHz amateur satellite service allocations.

Both transponders will have broad beam antennas to provide full coverage over about 1/3rd of the earth’s surface. Precise operational plans will be finalised over the coming months but it is anticipated that only quite simple ground equipment will be required to use this satellite.

A team of amateurs, led by Peter Guelzow DB2OS (President of AMSAT-DL) are providing technical support to this ground breaking project which is expected to provide an exciting new phase of activity for radio amateurs for the 21st century.

Amateur Television Quarterly

USA $20.00 year Canada $22.00 year DX $29.00 year (US $) Cyber: $15/yr

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) 338-6887

Digital Repeater TV DVB-S 1200 MHz 10 GHz

By IW5BDJ Fabrizio Bianchi, Siena JN53RH Italia

The DIGILITE project is a system that is based on the transmission of TV amateur type DVB-S.

Transmission from home is usually in the range assigned to us amateurs of the 1,200 MHz.

In Figure 1 we can see a block diagram of a digital transmitter.

Figure 1 Block Diagram

If we receive an issue that is not in line of sight, we must build a repeater and put it on a mountain that is seen by both correspondents.

The repeater receives 1240 -1290 MHz and converts it to 10440-10490 MHz, see Figure 3. To be able to receive the signals at home, we use a satellite dish, LNB and a satellite type decoder (Figure .4).

Units of the DIGILITE system (Figure 1) and the signal receiver DVB-S Figure 4 are well described in other articles, so here we will describe how to repeat the digital signal from the mountain.

Receiving Antennas 1200 MHz

We can get 2 antennas built on PCB in four quadrants, coupled with a coaxial coupler with a loss of 3 dB antenna.

The two antennas are mechanically supported by an aluminium sheet of 4 mm thick with dimensions 20X40 cm.

Between the pcb antenna's and aluminum base is added a thickness of 18 mm polystyrene foam with high density.

The top antenna is made with the lower antenna properly anchored and glued to the aluminium surface, visible in the photos Figure 5-6-7-8.

The connections of the 2 antennas are by 75 Ohm television coaxial cables and enter the coupler with coaxial input and output always at 75 ohms.

Figure 3 Block Diagram Digital Repeater

Figure 4 Repeater receiver system

Figure 5 The receiving antennas on FR4 and the polystyrene

Figure 6 The aluminium support

Figure 7 The receiving antenna

Figure 8 The antenna with the lid and support post

The antennas have been taken from an article by F5AD, Link: http://f5ad.free.fr/ANT-QSP_F5AD_Double-et-quadruple_Quad_1255.htm

Coaxial Coupler

The coaxial coupler is calculated to have input and output impedance of 75 ohms. It was built with copper plumbing pipes, according to the following formulae:

ZL for us will be 37.5, = 75/2, the point of union of the two 75 Ohm cables.

So we ZAcc = the square root of 75 X 37.5 = 53.033 Ohms

Now we need to calculate a long line Lambda \ 4 with impedance of 53.033 Ohm. According to the following formula, we can calculate the ratio between the diameters of the two concentric tubes and then adapt to the trade measures.

ZAcc= 138xLog = (D / d)

Where "D" is the inside diameter of the outer tube and "d" is the outer diameter of the inner tube.

So we have that log (D / d) = ZAcc/138

In our case we have Log (D / d) = 53.033/138 = 0.3843

And yet we have that the ratio of the diameter by 10 raised to 0.3843 D / d = 2.422

If we use a copper tube of 12 mm diameter, "D" inside is 10 mm and dividing by 2.422 "d" will be 10/2, 442 = 4.09 mm roundd down to 4mm.

The construction is shown in Figure 9

Figure 9 The coupler under construction

For the length of the pipe elements simply calculate Lambda \ 4 of the frequency that we want to use.

For example, for 1290 MHz we have: 300000/1290/4 = 58 mm

The center tube will then be exactly 58 mm long while the length of the outer tube will be such as to accommodate mechanical connectors which in my case are the type F to be able to adapt to the 75 ohm cable TV.

The Bandpass Filter.

The out of coupler enters a 5- stage bandpass filter with a bandwidth of about 40 MHz (1260-1300 MHz) with a loss of 1.5 dB.

The calculations for the size of the filter were performed with the program "Filtre.exe" and the the filter is made is made with copper sheet of 0.5 / 0.7 mm.

The filter is calculated using an input and output impedance of 75 ohms to match the input of the receiving module, BSDE8117A.

Details of the construction of the filter are shown in the Figure .9b & 10.

Figure 9b Construction of the filter

Figure 10 The finished Filter

The Receiver Module

The output of the filter P.B. goes to a line preamplifier with a gain of 20-25 dB in the band 1200 MHz and its output feeds the reception module type BSDE8-117A or equivalent. Figures 11 and 12

Figure 11 The receiver module, 9502150 MHz to 480 MHz IF

Figure 12 The line amplifier

The receiver module is driven by an I^2C line through the two signals SDA and SLC (data and clock), in addition to the need for a 5 volt power supply and a + 30 volts for the tuning of the varicap.

The module covers a reception band from 950 to 2150 MHz therefore suitable to receive our band 1240-1300 MHz.

Inside it has a PLL control circuit designed for digital satellite decoders, called SP5659. It has a much higher stability than the previous SP5055 PLL chip.

In order to control the tuning of the module, we used the circuit of IW2KGH. The file "SinSh v2.1", modified to fit the new integrated PLL, is in the link where you will also find all the instructions for construction: http://www.salpagno.it/ATV/Atv_sinto/AtvSinto.html

In Figure 13 we see the control circuit with the encoder for the tuning and three switches for other functions.

Figure 13 Receiver control module.

In addition to all this, the receiver module has a pin for the control of AGC (Automatic Gain Control). Remember that it is very important in digital TV systems to have a very high degree of linearity in amplification and conversion. The output of this module (on pin 12) is a converted IF signal at 480 MHz.

The output of this module on pin 12 have a converted signal IF at 480 MHz.

This IF signal must first be filtered with a filter with a bandwidth of 30 - 40 MHz and then amplified with a chain of amplifiers to bring its output to a level of 10 - 12 dB.

The 480 MHz Filter

The filter is made of tin-plate in a box the size of 72x72 mm as shown in Figures 14 and 15

Figure 14 480 MHz Filter drawing

Figure 15 Photo of the 480 MHz filter and further dimensions

The 480 MHz amplification chain

It is made from IF amplifiers found in old analog TV systems as seen in Figure 16. Inside there are Philips hybrid amplifiers (OM336OM339) with a bandwidth 40860 MHz, therefore suitable to amplify 480 MHz signals.

These circuits have a high dynamics and large amplification and are powered by 24 Volt to have a good linearity of the signal.

Furthermore, the chain composed of two hybrid amplifiers has a gain adjustment allowing to have an output between a minimum of 5 dB and a maximum of 15 dB, the signal more than sufficient to drive the mixer. Figure 16.

Figure 16 The 480 MHz amplifier with Philips hybrids recovered from surplus

All the parts so far described are housed in a box that is located in a framework sheltered from the rain.

From this box, a coaxial cable (75 Ohm) brings the signal and the 12 volt power to the rest of the converter, which is located in a sealed container on an external support pole with antennas for transmission and reception.

External Parts

The Mixer

The mixer is built on PCB laminate, 36x36mm, doublesided of high frequency type 5880 Rogers. Thickness 0.6 mm.

The mixer is built on PCB Laminate 36x36mm double-sided high frequency of type 5880 Rogers thickness 0.6 mm.

The Mixer is an SMD component from Hittite, type H220 and can work from 5 to 12 GHz, datasheet: http://www.hittite.com/content/documents/data_sheet/hmc220ms8.pdf

At the mixer, in addition to the IF signal, is the local oscillator at a frequency of 10 GHz, generated by a DRO circuit. The resulting output signals are 10000 +480 = 10480 and 10000 480 = 9520 MHz.

The Mixer output is directly in the cavity see Figure 16b.

Figure 16b The Mixer with exit directly into the cavity

The 10 GHz DRO oscillator

The form of the local oscillator 10 GHz is composed of a transistor of Siemens and a DRO which oscillates at a frequency around 10 GHz.

Again, this circuit is built on PCB laminate, doublesided high frequency type 5880 Rogers. Thickness 0.6 mm.

The circuit is based on an application of the transistor BFP405 Infineon published by Inineon at: http://www.infineon.com/dgdl/AN002.pdf?folderId=db3a304313b8b5a60113d4239297042f&fileId=db3a30431400ef6801142771e61c0770.

Details in Figures 17 and 18.

Figure 17 10 GHz DRO LO oscillator

Figure 18 Circuit diagram of DRO oscillator

The 10 GHz filter cavity

The output of the mixer we have a product that will be the sum of the conversion between the local oscillator at 10 GHz and 480 MHz IF, but we will also have the difference, something that we do not need and should therefore be eliminated.

We do this with a filter at its output and retain the signal of interest to us and that is the 10 GHz + 480 MHz signal.

The filter that we have adopted is a filter of the cavity-type with a bandwidth of 50 MHz and an insertion loss of 3 dB.

This filter was obtained from the notes of G3JVL. Link where you can see the project: http://www.microwave-museum.org/exhibits/mwm0023.htm

Some details in Figures 19, 20 and 21.

Figure 19 TThe filter built with Sma input / output connectors

Figure 20 Measurements for the 10 GHz filter

We can also use a filter found in old phone bridges as shown in Figure 21.

Figure 21 Surplus Mixer and 10 GHz filter

This filter has the same characteristics as the one built in house, only with steeper skirt characteristics, as it is studied by an industry and then is completely treated to internal Silver, however the function is the same.

So all output of these filters have a clean signal free from spurii that can reach the amp to be amplified to the desired power.

The Power Amplifier

This has been found in surplus. That is an amplifier that with a few milliwatts of input is capable of giving 800900 mWatts output in a band from 5.5 GHz to 13 GHz.

This is the Link: http://www.componentsandparts.com/Bible-Belt-/Jca-5-5-TO13-5-GHz-microwave-power-amplfier.idx

Some photos in Figures Figure 22, 23 and 24.

Figure 22

Figure 23

Figure 24

The signal from the filter at 10 GHz makes it's way through a guide / coaxial cable and enters this amplifier, that suitably fed with the 12 volts, provides 800 mWatts output. This signal, again through a coaxial cable / guide goes into a power monitor and then to the magic T. It is then divided for the 3 Horns.

This signal through a transaction Coaxial cable / guide goes into a power monitor and then moved to the magic T and then divided power for the 3 Horn.

The Figure 25 we see the power monitor.

Figure 25 The power monitor with Sma outlet for AGC

In Figure 26, we see a picture of the whole system, Mixer, Filter, Amplifier, Power monitor, magic T, 3 Horn Antennas.

Figure 26 The assembled system

At the output SMA Power monitor, we find a small part of the signal at 10 GHz, which uses a diode appropriate for this frequency and sends it to a circuit that amplifies this signal. It continuously sends out an appropriate phase and amplitude signal to pin 5 (AGC) of the receiver module.

Thus we have a control of both the input signal that the output power of the system.

The Magic T

The magic T is fed with the output of the amplifier and splits it into three parts.

A normal magic T with input into mouth 2 splits the power into two parts, mouth 1 and 3. Mouth 4 does not output any signal except for the return of stationary waves from any mismatching of the two outputs 1 and 3. See the Figure 27.

Here we see the Figure 27.

Figure 27 T Magic

So lets see now how do we split the signal into three parts.

We said that if we go with the signal into mouth 2 (Figure 27) we will have at outputs 1 and 3 a 3 dB signal and no signal on output 4, which is usually closed with a small ferrite to make any waves from the absorption of stationary waves caused by the mismatch of the antennas present at output 1 and 3, in other words, this output is the function of a circulator.

If we want to split the signal into 3 parts we have to use mouth 1 or 3 as an input.

In this case, suppose we input into mouth 1, we will have that signal divided into three parts roughly equal to the outputs 2, 3, 4.

The equality of the three output signals depends on the small mechanical devices that partialize the three outputs of the output 4 with bottlenecks and interference caused by a screw to divide the outputs 2 and 3.

In Figures 28 and 29 we see these divisor signal.

Figure 28 Here you can see a tab that partializes output 4

Figure 29 Here see the screw that partializes the signals at the outputs 2 and 3.

The construction of the transmit antennas at 10 GHz (Horn)

The three mouths of the magic T suitably partialized go to feed the three antennas at 10 GHz which are of the Horn type with a gain of 20 dB on paper.

For the construction of these Horn we referred to a program called Hdl_3b4, this is the link: http://www.qsl.net/n1bwt/. Look for the line as shown below and select Download

You will download the third beta test version (11/24/98) of the HDLANT program.

The horn can be constructed with double-sided epoxy glass thickness 1.5 mm or with the copper plate of thickness 0.7 - 0.8 mm.

This program calculates the area of the 4 (2 + 2) triangles that make up the Horn giving such data, frequency, size of the waveguide and desired gain.

With these parameters, the program generates an HDL file.Ps Figure 30 that once you get the printed pieces to glue the paper and cut out the double-sided epoxy glass or copper plate .

From the printout, you get horn, as shown in Figure 31 - 32.

Figure 30 The design that comes out of the program Hdl_3b4.exe with the desired data

Figure 31 the construction of the Horn

Figure 32 The Horn finished

A system like this is already installed on the mountain, Campi Chianti, from May 2014 with an optimal operation even though it has the double conversion as described in this article but does not have an AGC control to ensure the linearity range of the input signals and a constant power output.

Figure 33 The current transponder on Mount Campi

The system described in instead article is currently under construction in my lab, each piece has been tried tested and put into operation, but the whole set has yet to be tested and assembled.

Follow news anchor just about everything will be put in place.

Following photos of together. Figures 34 and 35

Figure 34 Set of digital transmitter, outside.

Figure 35 The Horn and the Magic T

MAX7456 OSD PC RS232 Serial Programming Interface

MIKE G7GTN

You may have the requirement to programme these OSD Modules from a PC that has only standard Serial Ports (RS232) available. If so this simple project might be of some interest.

Circuit description

The RS232 voltage level conversion to +5V is handled by a MAX232 (or similar from other manufacturers) part. This requires the 4 x 1µF electrolytic capacitors as shown. R2OUT is designated as the RESET output to the OSD Module. This is the pin marked GRN (DTR) on the physical module. The automatic reset for downloading would usually have a 100nf capacitor in this line. This is already fitted to the module directly to the processor RESET line and hence we require no duplication on our simple circuit.

Practical Implementation

It was easiest for me to construct this simple circuit on a small section of Veroboard. Connections to the OSD TX, RX & DTR pins were made using small female cable headers.

DATV-Express Project - July update report

Charles G4GUO received his ODROID U3 ARM-based micro-PC and began testing. He reported that the quadcore-ARM microprocessor running at 1.7 GHz has plenty of speed (compared to the Raspberry Pi) and the software repository by ODROID team has all the software needed to compile the kernel, etc. You can see in the picture below that the ODROID U3 comes standard with a large heatsink, and Charles reports the unit runs only warm, and there is no need for the optional fan kit. Charles is still learning how to spread out the processing load evenly over the four cores and is currently playing with the priority of the threads. One advantage of the quadcore-ARM on ODROID-U3 is the CPU speed(s) is fast enough to allow performing DVB-T 2 MHz bandwidth with full 4096-point iFFT math so that there are no nearby alias spurs in the spectrum.

Size of quadcore-ARM ODROID-U3 board is about the same size of Raspberry Pi

Charles has been adding code to allow the DATV-Express software to accept video streams using the UDP protocol. There is a lot of complexities involved but the current project preference is to let the video application (like FFMPEG) set-up all the PIDs, bit data-rate, etc. This effort is not completed, yet.

The project team has still not heard of any further progress by Hauppauge on releasing a Linux driver for their new HVR-1955/HVR-1975 MPEG2 encoder products. So Charles has looked at an alternative video-capture USB-device to perform the MPEG2 encoding for DATV. The EasyCAP (aka EZCAP) is a product that has been around for a long time.

Unfortunately, there are at least five different chip-sets that are being used to manufacture these devices…some work on linux, and others do not work. The chip set by Syntek called STK-1160 works OK, but there is a variation of that chip set that only supplies 8K audio?? A chip set called SAA-7113 works well also. The EasyCAP problem is that the sellers on e-bay or Amazon have no idea which chip set is being used in the product they sell. So the buy has to plug the device into the computer to identify what USB sees as the chip set. At $15 apiece (plus shipping), they are cheap enough to throw away if you get a wrong chip set. But, the project team needs to sort these chip set issues out and see if we can find a good supplier….before we release this EasyCAP code.

The project team has decided to not allow further research of EZCAP to hold up the release of the ARM code for DATV-Express for the ODROID-U3. Charles plans to move forward on preparing a Debian package to install the latest code for DATV-Express, including an installation for ARM that has been tested on ODROID-U3. Ken W6HHC has now received his ODROID and will begin testing Debian packages as soon as he returns from vacation towards the end of August. Charles plans to provide a DATV-Express presentation at BATC General Meeting in September. Ken plans to provide a DATV-Express presentation at TAPR Digital Comm Conference in September.

“moderate speed ahead”….de Ken W6HHC

TV Amateur

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://www.agaf.de/

Information

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 reading apps are ok providing that you have a 3G 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.

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.

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