Generating Digital RF?

Digital ATV - The latest generation, cutting edge ATV - Please discuss it all here.
Forum rules
This forum is run by the BATC (British Amateur Television Club), it is service made freely available to all interested parties, please do not abuse this privilege.

Thank you
Post Reply
aiqy65
Posts: 16
Joined: Thu Oct 02, 2008 12:06 pm

Generating Digital RF?

Post by aiqy65 » Fri Oct 17, 2008 2:02 pm

A trawl of the internet gives me lots of ways of filtering and generating lots of RF but I seem to be missing quite an important bit. (don't say its genetic..)

What are you guys using to take a video signal, mpeg it and then modulate something?

That seems to be the 'missing box' in all the pictures etc I have seen.

Cheers
Lee
G4TNX

justinf
Posts: 1
Joined: Thu Nov 20, 2008 7:12 pm

Re: Generating Digital RF?

Post by justinf » Thu Nov 20, 2008 7:45 pm

Hi, I notice no reply for over a month so let me give it a go.

To borrow the concept from SPARS ( http://en.wikipedia.org/wiki/SPARS_Code ) ... The path differs depending on your source being digital or analogue.

A pure "DDD" digital path using say SR-Systems boards ( http://www.sr-systems.de/V02/content.ph ... &style=std ) might look like this:

Digital camera --> Firewire --> Mac/PC --> AES/EBU + HDMI to SDI --> SDI to ITU 656 --> ITU 656 to DVB ASI/SPI (DVB MPEG2 TS) --> DVB TS to L band (RF) -> Filter+AMP -> ANT

I would assume most people are using the "AAD" approach (everything analogue except the TX), which (using the RS boards again) might look something like this:

Analogue camera --> video baseband + audio --> [ optional mixer / TBC etc ] --> Analogue to DVB ASI/SPI (DVB MPEG2 TS) --> DVB TS to L band (RF) --> Filter + AMP --> ANT

Let me know if that helps or simply confuses more, it might be easier for me to draw it.


Justin

Post Reply

Return to “DATV - Digital ATV”