BATC Forum

Yesterday we succeed to make a DATV transponder/relay, full digital, using Digilite and Tutioune.

Tutioune receive 437 Mhz via a converter 437--> 1337 Mhz and a Tuner card(TT S2 3200)
I just switch on the Tutioune UDP button.
Digilite transmit receive the stream and send it to the Digilite board on 1255 Mhz.

Absolutely no processing. very few delay in re-transmission as the stream is sent as soon as it is received by Tutioune.
the use is immediate for anyone that has already installed the 2 softwares : Tutioune and Digilite Transmit. We have made many tests yesterday, F5AG0 transmitting on 437Mhz, my Tutioune retransmitting on 1255Mhz to two others OM : F5UOU and F6FWZ.
(F6FWZ has no converter and no 437Mhz antenna, so it was the first time he could receive the F5AGO 437Mhz DATV signal.)

it could be done in reverse transponder : 1255Mhz input and 437 Mhz output.

I'm thinking that, If we work a little the software part, it could be easy to demux the TS received, add a second service, for example a live video of Tutioune Vumeters and constellations ... and send both services in one stream, adding the possibility to change the SR.

The second generation of DVB-S demodulator like the STB0899 never need to know the PID as they can find it automatically.
So we know that PID values are not a problem since few years and we can use any PID we want, a good receiver find PID automatically, just to give frequency and SR ( there is a SR search function in the chip, but it take times)

Last generation of DVB-S demodulator chips like STV0903 or professional STV0900 with double demodulator can give us more possibilities in future: they have now the "blindscan" feature that let them find the SR.
So with this kind of chips, we have just to give the frequency.
A DATV repeater will be satisfied to use this function, any OM could enter in the DATV Repeater with it's own SR and PID....doesn't matter.

The future is in front of us..

Jean Pierre F6DZP

I did something similar with GraphEdit and it worked well going from 1249MHz to 437MHz.

For simplicity and to keep the symbol rate and timing the same, maybe the padding packets on PID 8191 could be used to insert extra information. It would still be necessary to change the PAT and possibly the PMT. Perhaps the Tutioune screen could be coded as a digital subtitle and then the receiver could display it when requested. DigiLite has 5% of padding, so that's 400k bits per second at 4MS that could be used for something else.

I think some software to change the incoming PIDs to a standard set for output would be good. Several receivers, such as the Fortec Star 4000 and 4200 will not display a picture if the PIDs are different from when the original transmission was scanned.

Just to clarify, these experiments are being done with the UDP input to DL Transmit v2, which is still being tested and is not yet generally available.

Brian