DATV-Express Project - June update report

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DATV-Express Project - June update report

Postby KenW6HHC » Fri Jun 30, 2017 1:04 pm

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/hjsbblik5gpgj ... 5.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/window ... mesdr/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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Re: DATV-Express Project - June update report

Postby g8vpg » Fri Jun 30, 2017 3:42 pm

I would certainly be interested in a frequency range extender board for the DATV Express.
73 Shaun G8VPG.

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Re: DATV-Express Project - June update report

Postby G4GUO » Fri Jun 30, 2017 4:08 pm

Hi Shaun, the extender is very much work in progress but we are aiming to make
it universal so it will work with other brands of DATV Transmitter.

It is a matter of deciding a budget then seeing what RF goodies we can cram on
the board for the price.

- Charles

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Re: DATV-Express Project - June update report

Postby G8XZD-TV » Fri Jun 30, 2017 7:55 pm

Am interested as well. Ian.

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Re: DATV-Express Project - June update report

Postby G8GKQ » Sat Jul 01, 2017 8:16 am

If the Express Frequency Extender goes into production, I would aim to add the functionality to the Portsdown Transmitter so that it could drive the frequency extender as well. This would involve the Portsdown driving the i2c control for the VCO, and some changes to allow band selection from the touchscreen.

So the possible combinations might then include:

- Portsdown with filter-modulator board driving Express Frequency Extender

- Portsdown driving DATV Express board driving Express Frequency Extender

- PC driving DATV Express board driving Express Frequency Extender


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Re: DATV-Express Project - June update report

Postby G8DKC » Sat Jul 01, 2017 9:19 am


Just adding my support for a great idea :-)


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