Software for filter/modulator board

Discussion about this major DATV Project. See https://wiki.batc.org.uk/The_Portsdown_Transmitter
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g8vpg
Posts: 387
Joined: Fri Oct 11, 2013 9:35 am

Software for filter/modulator board

Post by g8vpg » Tue Sep 22, 2020 3:19 pm

I am trying to build a software installation for an older Portsdown with the filter/modulator board, using a Pi 3B+. Portsdown 2020 doesn't seem to run very well. MPEG2 transmission has short breaks in the transmission and H264 barely works at all. I thought I would try a 2018/19 stretch based installation, but the GitHub page instructions no longer seem to work. The installation finished after 10 minutes or so with lots of unmet dependency messages and it does not run and I cannot ssh into it. What is the best way to build a new card for use only with the Portsdown filter/modulator board?
73 Shaun.

g0mjw
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Joined: Sat Sep 20, 2014 9:15 am

Re: Software for filter/modulator board

Post by g0mjw » Tue Sep 22, 2020 3:48 pm

My old 2018 Portsdown is working fine with the filter-modulator board. It's on the July update which I think was the last. Perhaps try building with the February 13th 2020 Buster lite? You will have saved a copy of course but if not https://downloads.raspberrypi.org/raspbian/images/

Mike

Edit - lite is here http://downloads.raspberrypi.org/raspbian_lite/images/, not there.

G8GKQ
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Re: Software for filter/modulator board

Post by G8GKQ » Tue Sep 22, 2020 4:30 pm

Hi Shaun

What video source are you using, and what SR/FEC?

Portsdown 2020 built on the February version of Raspbian should be the version that you want. Nothing else will build.

Dave

g8vpg
Posts: 387
Joined: Fri Oct 11, 2013 9:35 am

Re: Software for filter/modulator board

Post by g8vpg » Wed Sep 23, 2020 9:51 am

Thank you Dave,
I have now found the list and table of compatible modes and sources and it is working in accordance with this. Is there a table of SR/FEC combinations that are known not to work?

73 Shaun.

G8GKQ
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Re: Software for filter/modulator board

Post by G8GKQ » Wed Sep 23, 2020 10:25 am

Hi Shaun

I have recently been concentrating on getting the Low SR modes working properly with the Lime for QO-100, but have updated some bits that might affect higher SR modes with the F-M board.

I did publish this table of SRs and FECs a while ago which might still be valid viewtopic.php?f=103&t=6070#p19583. If nothing else, it gives you an idea of the complexity of the problem.

Dave

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