[Argus25]

Chris,

I would echo the words of 1100 man.

With your level of experience here, there will only be so much you can do.

You can do all the basic checks and it might be possible that you will find the fault still.

The Tuner unit and IF in a TV set of this vintage is a moderately complex arrangement for a beginner to tackle.

When the tuner is working properly the very small level incoming antenna signal is amplified by one tube and mixed (beats with) with a signal from the other tuner tube which is the local oscillator.

The beat note, or hetrodyne if you like, is a down converted frequency for the sound and vision signals that comes out of the tuner and is passed to the video intermediate frequency amplifier (IF). So for starters the tuner has to be working properly and on the correct channel setting with respect to the signal you are feeding it.

The the video IF has to be working and have the correct band pass response. Meaning that all the small screw adjustments in the coils there have to be set right (Hopefully they won't have been touched in the recent past).

The sound signal is extracted out of the video IF at the detector with a 4.5MHz beat note between the sound and vision signals (which are transmitted 4.5MHz apart) and fed to the sound IF and FM detector circuits, then on to the audio amplifier. This is called "Intercarrier sound"

If there is an excessive sound carrier signal, or response in the video IF for the sound carrier signal, it will break through into the video signal and modulate the picture. Or if the sound traps are not set right it can also break through.

Also with adjustment errors, a picture buzz can end up in the sound channel.

Assuming none of these multiple adjustments in the video and audio IF stages have been touched, the problem could still relate to a faulty component. But it might be, that to get it working you will need some help from someone with the equipment to go through it systematically and sort it out. But I think you have done very well so far.

One approach I could suggest, since its getting a bit frustrating for you could be, put the set aside for a while. See if you can get a copy of Grob's book Basic Television 2nd Edn McGraw-Hill. This explains everything you would need to ultimately fix it yourself if you got stuck and couldn't get help. Its a good book for home study. There is a lot to learn, but it would be worth it.