DIY DVB-T transmitter with VGA card

Zaphod

http://fabrice.bellard.free.fr/dvbt/

zilog_jones

Wow O_O
Wonder if he's working on getting actual video output from this?

watty

It's not very usefull. You can either buy an PCI card or a bench test set.

You'd need a licence. In theory at 436MHz and 1.2GHz a wireless experimenter licence might do.

I think that's quite an old article.

Interesting though.

rogue-entity

This is an interesting Proof of Concept idea, and if it can generate a stable video, then it would be a very cheap way of sending the output of your PC as a DVB-T signal. Correct me if I am wrong, but isnt this much cheaper then buying a DVB Bench Test kit or PCI card? I mean, I was toying with the idea of taking in multiple DVB-T signals, say from the UK Freeview system, and our own potential system, and merging them together, perhaps with another "channel" or two, and sending them around the house.

The main motivation being that in our house, we have many TVs, and I have them all tuned to the same channel, and would love if the TVs were smart enough to retreive a channel list from an external sorce so I wouldnt have to retune them if I changed the channel order, or if NTL did and I had to retune to sort it back the way I want.

I would love to experiment with DVB-T transmission, and if the gear was cheap enough, I would also be tempted to rebroadcast RTE 1, 2, TV3, TG-4, BBC1, BBC2, ITV, Channel 4 as received off-air, in DVB-T. But its a lot of work for something that is probably illegal. It has made me wonder, with many knowledgeable people calling for a national DTT service, why none of the Deflectors have tried rebroadcasting the terrestrial channels as DTT, or experimenting with wide-band repeaters to rebroadcast and deflect the UK Freeview system (would love that here, but no reception in Waterford).

Still this is an intersting experiment.

Ulsterman 1690

Someone was asking about starting a pitate TV station a few Months back -well if you had this with some filtering and amplification........:D

As for beaming it around the house well its technically illegal (mmmmkaayyyy) but if you do it you need to be careful about picking a really clear channel (not one that just "looks clear" to you) so that you dont upset any neighbours who might get their TV from some obscure distant transmitter and watch out for those pesky adjacent/n-5/n+9 channel relationships as well

Sponge Bob

pirate TV stations could attract lots of attention from Comreg

Its illegal to broadcast on those frequencies mentiioned above but there are ISM bands where it may be allowed at low power. Videosenders often use the 2.4ghz ism band also used by wi-fi .

watty

rogue-entity wrote:

This is an interesting Proof of Concept idea,

Still this is an intersting experiment.

Yes an intersting toy. It can just about generate a test card or manage one stream, badly.



I have found no cheap real time solution to demuxing and remuxing DVB. If anyone knows one I'm your friend.

I can't find a solution to recieve N channels and remux as M channels under 10,000 never mind cost of Modulator.

Ideally to you might want to convert a mix of analogue, DTT MPEG2, DVB-s (Sat) MPEG2 from a half dozen receivers and re-encode as SD MPEG4 and create a MPEG2 TS with 16 MPEG4 channels in SD in it.

For "personal use" DVB-s modulation is the cheapest and simplest. DVB-c next and DVB-t is the most expensive. The DVB-T PCI card I looked at create DVB-H simulatously for your Nokia N93 or whatever.

Actually at the higher 5Ghz ish Licence free ISM band DVB-s is fine terrestrially on point to point dish links . DVB-c OK too (NTL use DVB-c on 2.5GHz MMDS) An MMDS down converter will output at about 200MHz maybe from 2.4Ghz?

Sponge Bob

watty wrote:

An MMDS down converter will output at about 200MHz maybe from 2.4Ghz?

mmmmMM , have one in my attic

rogue-entity

I had posted a reply here.. but it dissappeared

Anywho, I wasnt in the area of starting a pirate TV channel, I was musing with the idea of taking in multiple digital feeds and merging them into one feed for a single DTT STB, and perhaps distribute this combined signal for other STBs on other TVs. But, as watty said, it would be easier to do what your typical cable company does, take in multiple feeds and recode them into DVB and transmit this signal around the house. This same feed could be broadcast either on the unlicenced 2.4GHz band, or on a licenced frequency with a wireless experimenters licence, if applicable. Setting up a local community television service would need professional gear to be done right, and DVB Encoding, modulating gear is prohibitivly expensive, as Watty just said, and as he also said, he is the best person here to go to for such stuff.