Portsdown 4 Update with LongMynd improvements

Discussion about this major DATV Project. See also https://wiki.batc.org.uk/The_Portsdown_Transmitter
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G8GKQ
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Portsdown 4 Update with LongMynd improvements

Post by G8GKQ » Sun Oct 18, 2020 2:58 pm

I have just released an update for the Portsdown 4 which includes the latest, most reliable, version of the LongMynd receive software, and also adds the "5th harmonic mode" to the Portsdown Pluto Signal Generator, extending its coverage (at very low power) to well above 10 GHz. The full list of notable changes:
  • LongMynd software now recovers from slow tuner VCO locks and does not freeze.
  • Pluto Signal Generator has a "5th harmonic mode" potentially providing a signal source up to 30 GHz.
  • The user's original Langstone Configuration file is restored after a Langstone update
  • Langstone stop command (on selection from Portsdown) has been removed to prevent the Langstone hanging during start.
I would encourage all Portsdown 4 users to perform this update, as there have been a number of new features added recently.

Dave, G8GKQ

radiogareth
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Re: Portsdown 4 Update with LongMynd improvements

Post by radiogareth » Sun Oct 18, 2020 3:21 pm

Worked for me, great update :-)
Would modulation on the sig gen be a future possibility?
Thanks for all the work on this :-)

Gareth

F4DVK
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Re: Portsdown 4 Update with LongMynd improvements

Post by F4DVK » Fri Oct 23, 2020 6:46 pm

Hi Dave,

A friend just tried DVB-S FEC 7/8 with pluto, but it doesn't work. Do you have any idea of ​​the problem?

Thank you,
Stephane.

g0mjw
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Re: Portsdown 4 Update with LongMynd improvements

Post by g0mjw » Fri Oct 23, 2020 7:39 pm

DVB-S? Sounds like it might be for a repeater. At what bit rate? Pluto doesn't do high rates.

G8GKQ
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Re: Portsdown 4 Update with LongMynd improvements

Post by G8GKQ » Fri Oct 23, 2020 8:50 pm

Hi Stephane

I have just reproduced the problem, but can't see why it does not work. DVB-S FEC 5/6 does not work either.

Maybe Evariste has some ideas? (I'm using Firm2101RC dated 5 February 2020 and simply feeding it rtmp). For 333kS FEC 7/8 the video bitrate is 345856, and the audio bitrate is 64k.

Dave

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