How could I make a possible analogue home transmitter?

[Nic-15fl]

What I'm talking about is I have these two analogue televisions, both a Beovisions, one from 1990 and one from 1974 and the 70's TV is colour. Since they have an antenna in both of them I was thinking mostly for the TV box and VCR machine and blue-ray player so I can watch on both televisions without needing extra wires, theyre all SCART components.

[julie_m]

What you want is a modulator. Any old VCR will do the job. Some people have had success repurposing the TV modulators from PlayStations, camcorders or home CCTV systems.

[mark pirate]

I use a little transmitter called a 'Video sender', this takes a composite video signal and audio from a video recorder, DVD player or digital box and sends it to the TV.

All that is needed is a set top aerial on the TV, and tune to the transmitter.
Mine is for the UK 625 Pal standard, but you may find one to suit your TV system.

Mark

[Nic-15fl]

Can it take stereo audio too?

[G6Tanuki]

I don't think SCART supports Blu-Ray; it'd be a violation of the anti-copying protocols (which is one of the reasons HDMI was introduced).

[Nic-15fl]

this blue ray have option for composite out,

[paulsherwin]

Originally Posted by G6Tanuki

I don't think SCART supports Blu-Ray; it'd be a violation of the anti-copying protocols (which is one of the reasons HDMI was introduced).

Many players downsample to SD for use with analogue connections. The copying restrictions only apply when the signal is still HD digital.

That said, SCART connectors are becoming much less common on both Blu-ray and upsampling DVD players, particularly at the bottom end of the market. This is just a cost cutting measure.

[mark pirate]

Can it take stereo audio too?

No, just mono. I use it connected to a digital box to broadcast to my 625 line sets, most of which do not have any form of AV inputs.

Mark

[Hunts smoothing bomb]

Mark can you still buy that model? I had one exactly like that over 20 years ago!

Cheers

[Nic-15fl]

There are stil a few scart parts out there, so it is possible yet but how is that copyright related? i simply want a way to broadcast to the analog stereo tv's.

[mark pirate]

Hi Lee, I bought mine years ago from a friend, and recently bought an identical one from a boot sale.
These date from the early 90's, but worth keeping an eye on ebay for one.
I am sure it is possible to build something similar, the circuit looks pretty basic and could probably be improved upon. I would certainly like a 405 VHF version!

Mark

[pichacker]

The problem you have just using any of the available modulators is that the sound will only be mono. Not sure it your TV would be NICAM or a Zwie-Tone type of arrangement.

I don't recall any stereo modulators on the domestic market.

[SiriusHardware]

Originally Posted by Nic-15fl

There are stil a few scart parts out there, so it is possible yet but how is that copyright related? i simply want a way to broadcast to the analog stereo tv's.

Nic, If I correctly understand what it is that you want to do (receive stereo analogue signals off-air through the TV aerial socket / tuner), your sender project / device would have to include a NICAM sound encoder.

Chipsets for receiving / decoding NICAM must have been abundant as every NICAM compatible stereo TV would have needed one, but generally speaking, NICAM encoding would normally only have been done by the broadcasters. A UHF video sender which incorporates a NICAM encoder is probably a rare thing indeed.

It's the sort of exotic project which Elektor or ETI (hobby electronics magazines) might have possibly have tackled at one time or another - maybe someone has just such an article lying about?

[KeithsTV]

There was a Nicam encoder IC, MC44C404 from Freescale (formerly Motorola) which could be used with the MC44BS373/4 UHF modulator to create a suitable signal for NICAM receivers but the datasheet is only the advance version so I don't know if it ever went into full production.

Keith

[Hybrid tellies]

Keeping it legal I use the built in modulator of my VCR, via an aerial distribution amp to feed an analogue UHF 625 line PAL signal to all my older 625 line sets around the workshop. I then feed into the VCR socket via a scart switch my Freeview box and DVD so I can watch any Freeview channel plus DVD and of course watch video tapes and record programmes on my VCR. I considered using some kind of video sender for the rest of the house but changed my mind as the number UHF TV channels free from local Freeview transmitters are very few with the risk of causing interference being quite high.
I have recently bought a modulator, from Amazon. Which covers all the 625 TV channels on VHF and UHF with the sound spacing adjustable from 5.5, 6 and 6.5Mhz, in mono only, which would meet your requirements.
As has been said stereo sound is another challenge.

[Synchrodyne]

There was a NICAM encoder mentioned in this thread: https://www.vintage-radio.net/forum/....php?t=114544; but it was a professional unit not a domestic model.

Cheers,

[llama]

Are your TVs stereo?

The 1970s one is said to be colour. So is the 1990s one monochrome?

Maybe OP only wants to take stereo in and is happy to play in mono. Especially if the TVs are mono anyway!

Graham

[Nic-15fl]

I have a varity of tv's, some stereo, some mono.

[ntscuser]

Originally Posted by pichacker

Not sure it your TV would be NICAM or a Zwie-Tone type of arrangement.

B&O often had both.

Stand-alone A2 stereo modulators are available from firms like Terra. They work on bands I, III and UHF.