Murphy A 252
 

I thought it was high time I switched on my late father's Murphy table radio Model A 252 as it had been neglected for a while. Now when I switched it on, the volume control seems to have lost the first part of its track, as the sound bursts in after control has rotated a small amount. Sound is fine with no hint of distortion, so it this just a simple pot change or could there be something else here?
Mike.

Re: Murphy A 252
 

Try a squirt of Servisol before doing anything more drastic.

Re: Murphy A 252
 

I have switch cleaner, probably RS, not sure. If that fails I could bridge out the pot with a known good pot and see what happens.
These old Murphy sets give out a good tone. Nor sure if they are push pull without looking at the circuit.
Mike.

Re: Murphy A 252
 

Remember that it will have dodgy capacitors by now if unrestored, even though it's a family heirloom.

Not push pull, but a good quality set. I think it was Murphy's first model with VHF.

Re: Murphy A 252
 

Yes, a good AM/FM radio, but Murphy's first was the very similarly styled A242.

As Paul says, there will be quite a few paper dielectric capacitors to replace, especially the "infamous" one that couples the audio signal to the control grid of the audio output valve (Mazda 6P1 in the case of the A252).

Its circuit reference is C76 in the official Murphy circuit diagram (10nF = 0.01uF). If it's leaky, it can damage the 6P1 and/or the audio output transformer. So, it should be replaced before the set is run for an extended period of time.

Re: Murphy A 252
 

Thanks for info, will check that cap out.
Mike.