What is the oldest tv you still use?

The state of it - I think everything in it is potentially lethal if powered. (Capacitors in particular will probably go bang loudly...)

I bought it many years ago to stop it going to land fill. I keep meaning to find someone to restore it. (No idea if even the tube is still functional)

Make sure if you find someone, they fit a DVB-T2 tuner at the front end

Given that modern graphics cards can be persuaded to generate 377i25 output I suspect that won't be tricky , but it would need a System A modulator...

DSP techniques might be the solution for the System A modulator ?

There is software available for the HackRF called HackTV which can directly generate analogue TV signals you can plug straight in to a TV. Looking at it, it does seem to have support for System A, likely untested however.

Yes - SDR would make sense - but integrating that into a 'real world' live TV system is non-trivial.


AIUI there are off-the-shelf modulator chips that do a good job - though you need to use a pair of them to cope with the non-standard sound/vision carrier offset.

I have never understood why very few 405 line TVs had audio and video I/O sockets on them enabling users to bypass the demodulator - or test / use its output.

The live mains chassis was one reason. Back in the 50s and 60s, what would you have done with baseband video domestically ? And where would you have had baseband video from to inject into the TV ?!!

Audio was a slightly different matter, and some enthusiasts (inc my grandfather) did fit an isolation transformer to extract the audio to feed to an amplifier. However home HiFi etc was in its infancy back then, so so little demand, no manufacturer was going to provide the facility.

Might be wise to post pictures of said TVs as some will just be lying to out do fellow posters.

Ease of testing is one advantage of having the output of the demodulator and the input of the monitor and audio circuitry available. There is also the option of using the TV with a video camera, in a CCTV system, or connecting the output of one TV to the input of another TV. Schools used to do this in the 1970s when TVs with audio and video sockets became available.

I once encountered a 405 line TV that had a plug which connected the output of the demodulator and the input of the monitor and audio circuitry. I'm not sure whether the socket was to specifically connect anything or primarily intended for testing.

None of that is what I'd term normal domestic use, which means most domestic market tellies wouldn't have been equipped (too expensive for a mass produced item) You're talking about industrial use really.
It wasn't until the early 80s, when it became desirable for home computers etc not to have RF interfaces that
baseband inputs started to appear. We had a 1980 Grundig that had a DIN socket for AV connectivity

For the benefit of 'all_night'

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwiv7tiQ0JrfAhUkyoUKHVb3D2IQjRx6BAgBEAU&url=http%3A%2F%2Fobsoletetellyemuseum.blogspot.com%2F2011%2F04%2Fgrundig-super-color-stereo-56-16599.html&psig=AOvVaw3asYfjLW87yaUpgfG9m8l_&ust=1544715579471264

Domestic TVs are not the most pleasant machines to repair and service. Any design features that makes it easier are more than welcome. The very worst examples are the dual standard 405 / 625 line colour models as they are very complicated with a large number of components. A 1950s all valve 405 line TV is actually quite simple in comparison. In contrast, much TV broadcasting and production equipment up to the late 20th century is designed in a way that's much easier to work on than consumer electronics.