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First commercial sat RX found which supports RB-TV <1MS

Posted: Wed Jul 25, 2018 3:25 pm
by gw8bvi
Severnside ATV Group has found what we believe to be the first commercially available satellite receiver box which supports symbol rates below 1MS/s

It works down to 250 kS/s DVB-S, and down to 400 kS/s DVB-S2 QPSK (250 kS/s 16APSK).
It supports the de-facto RB-TV symbol rate of 333 kS/s, 7/8 FEC.

Up until now you were restricted to using Minitiouner for receiving low symbol rates below 1MS/s.
The unit is the ZGemma H9S Enigma 2 Linux smart box. Other satellite receivers are available, and we will continue testing others hoping to discover more that support low symbol rate RB-TV.

The unit needs to be used with an RX upconverter such as the SUP2400 (BATC shop) for 70cm, because unlike Minitiouner v2 (BATC shop) the H9S tuner only covers the standard 950 to 2150 MHz satellite IF band.
For the new NoV 2m allocation at 146.5 MHz you will need a 2m to 70cm upconverter + SUP2400, or a 2m to 23cm direct upconverter (the SUP2400 doesn't work below 250 MHz input).

The H9S supports Mpeg2, H.264 and H.265
I tried it with 333 kS/s H.265 DVB-S from my DATV Express exciter, and the results were excellent.
The setup menu is very non-intuitive, so I intend to write up a guide for CQTV.
The H9S tunes 23cm DVB-S directly. I had it decoding GB3ZZ's 4MS/s digital output, which is a two channel multiplex - no problem once manually tuned in.

Phil GW8BVI, Caldicot S.Wales

Re: First commercial sat RX found which supports RB-TV <1MS

Posted: Thu Aug 02, 2018 4:28 pm
by G8XZD-TV
Very interesting find, thanks Phil.
Have you tested how does it performs over the air - say compared to say Minitioune and a SUP2400?
I know some of the "do everything" receivers take an age to lock up
So in your opinion would it be a good one for repeater service or too fiddly?

73. Ian, G8XZD.

Re: First commercial sat RX found which supports RB-TV <1MS

Posted: Sun Aug 05, 2018 5:12 pm
by M0DTS
as above, i would be interested in it's performance compared to minitioune at 333 ks for example inc decode delays.

Rob

Re: First commercial sat RX found which supports RB-TV <1MS

Posted: Tue Sep 11, 2018 12:08 pm
by gw8bvi
Hi All, I still have the unit on loan but haven't had any time to go on air and test the zGemma at 333kS/s RBTV to see how it compares with Minitiouner for lock time etc. It would be interesting to see how stable it is for use at a repeater site, and what it does after power loss / restore. 73, Phil GW8BVI