06-05-2012, 11:47 AM
I bought this a while ago and started work on it a couple of weeks ago. Unfortunately I forgot to take 'before' piccies but trust me, it was not nice to look at or handle.
Luckily it had its full complement of valves including, thankfully, its U50. I have subbed 5Y3GTs for these on other GEC sets I have that are missing them but I prefer the proper valves of course. I never seem to have much luck with reforming the main smoothing capacitors and didn't again here so the can was cut open and new capacitors stuffed inside.
After changing the output valves AF coupling capacitor I gave it some volts through the lamp limiter and noise started to come out of the speaker. However, this was not the noise I wanted to hear, more like a slow and quite loud 'phut-phut' which didn't change with the frequency, wave or volume controls. Of course it was 'motor-boating'. The smoothers had been changed so it can't have been them so I bridged each capacitor with a 0.1uF until the noise went away. It turned out to be the AGC decoupling capactor. This was changed and the set now worked nicely.
The inside were cleaned and the case polished, knobs went in an ultrasonic bath. Scratches on the gold facia were painted out with a mix of Humbrol metallics.
Andrew
Luckily it had its full complement of valves including, thankfully, its U50. I have subbed 5Y3GTs for these on other GEC sets I have that are missing them but I prefer the proper valves of course. I never seem to have much luck with reforming the main smoothing capacitors and didn't again here so the can was cut open and new capacitors stuffed inside.
After changing the output valves AF coupling capacitor I gave it some volts through the lamp limiter and noise started to come out of the speaker. However, this was not the noise I wanted to hear, more like a slow and quite loud 'phut-phut' which didn't change with the frequency, wave or volume controls. Of course it was 'motor-boating'. The smoothers had been changed so it can't have been them so I bridged each capacitor with a 0.1uF until the noise went away. It turned out to be the AGC decoupling capactor. This was changed and the set now worked nicely.
The inside were cleaned and the case polished, knobs went in an ultrasonic bath. Scratches on the gold facia were painted out with a mix of Humbrol metallics.
Andrew
