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DATV on 5.6Ghz

Posted: Mon Sep 11, 2023 2:32 pm
by G6MNJ
Spurred on by the availability of FPV FM ATV kit it struck me why not investigate DATV on this band and so with a Pluto set to 6Ghz max frequency and the prospect of F5OEO Portsdown or other it seemed reasonably straightforward to make a TX signal.

However RX was a little more challenging and it is here I ask for suggestions. Clearly the Minitiouner and software would be a obvious choice but the Serit tuner will not directly tune to 5.6Ghz. So I thought C band to L band converter maybe? But of course they were from a time when the world was analogue and almost certainly not frequency stable enough for DATV.

So people what do you suggest to get a received 5.6Ghz DATV signal down in frequency to fee into a Minitioune?

73 Paul G6MNJ

Re: DATV on 5.6Ghz

Posted: Mon Sep 11, 2023 2:50 pm
by radiogareth
Been there and done that Paul, as follows.....
Portsdown4 and Pluto 'for the brave' stops at around 4.3GHz, something to do with a 32bit overflow...
However, ExpressDVB Transmitter software will work at the required frequency but can be tricky to decode as its apparently a bit rough around the edges.
If you drive the Pluto with 0303 software from a PC with DATVEasy 2.17 it will generate without issues.
For RX, I used a real 'wing and prayer' solution. Antenna into a filter, then a suitable mixer with IF provided by an eBay keyboard ADF4351, then pipe-cap filter to let 3.4GHz through.
Then into a probe (sma+1/4 wave) mounted in the side of a Titanium 3.4GHz C band LNB, then IF out to the RX. I was amazed that it worked, but it did, although sometimes prone to oscillation.
I'm now building a combined 9cm & 6cm box with big PAs and using an Ionica 3.4 front end for 9 (they are good) and a similar down-conversion process from 6cm to 9cm (Mixer and LO & Filters).
Its on the bench for this winter finishing.....
Good luck...
Gareth