Reply by Satech January 11, 20062006-01-11
>I know there is a valid transport stream coming out of the PBI encoder >as >i can receive & decode it via my Promax P4+C spectrum analyser which >has >an RS 422 parrallel TS input (DB 25) & QPSK card. > >Did you mean Transport stream analyzer???? > >You might also post in the sci.engr.television groups.... > >Mark > >
Thanks Mark, We used a Rhode & Shwartz TS analyser to ascertain the true bit rate coming out of the PBI encoder (10.799 MB/sec). We then fed the same transport stream into a Promax P4+C RF spectrum analyser which also has TS input. The Promax doesn't analyse the TS as such - it is able to receive the TS (SPI DVB)using a DB25 input connector. Using an inbuilt QPSK card, it is able to demodulate the TS to audio/video on the built in colour LCD screen. We can also do this with the 33.75 MB/sec TS from a satellite mux. So,it makes me wonder what is different between the two transport streams that the DMV system 3000 modulator doesn't like. Thanks Steve Johnson
Reply by Mark January 11, 20062006-01-11
I know there is a valid transport stream coming out of the PBI encoder
as
i can receive & decode it via my Promax P4+C spectrum analyser which
has
an RS 422 parrallel TS input (DB 25) & QPSK card.

Did you mean Transport stream analyzer????

You might also post in the sci.engr.television  groups....

Mark

Reply by Satech January 11, 20062006-01-11
Hello group,

I am having problems getting a PBI  DCH-2000EC  MPEG-2 encoder to operate
correctly with a DMV system 3000 MPEG-2 modulator via RS 422 parrallel. I
know it is not a problem with the modulator as it operates OK when using a
different MPEG-2 transport stream from an Alteia professional grade QPSK
satellite receiver (with a bitrate of 33.75 MB/sec from an active
satellite mux). When i swap to the PBI transport stream & adjust the
modulators receive bitrate to the PBI's output bitrate (in this case
10.799 MB/sec, which we know to be correct from using a Rhode & Shwartz
transport stream processor), the modulator recognises the clock & phase
locks to it - but, there is no frame lock & input lock.

Even though the encoder has ASI & SPI  RS422 (DB25) outputs, the ex TVNZ
modulator only has SPI  RS422 (DB25) input.

My question is:

Is there a difference between the two transport streams - is there
something missing from the PBI's transport stream that is required by the
DMV modulator to lock correctly? (PMT or PAT tables for instance). Does
the PBI encoder require a multiplexer which inserts extra data
information, maybe.

I know there is a valid transport stream coming out of the PBI encoder as
i can receive & decode it via my Promax P4+C spectrum analyser which has
an RS 422 parrallel TS input (DB 25) & QPSK card. This is also the case
with the transport stream from the Alteia sat receiver.

I am quickly running out of options - Can you please help. Any advise
would be much appreciated.


Kindest Regards

Steve Johnson
Satcom (NZ) Limited
Pukekohe, Sth Auckland, NZ