12-04-2011, 04:59 PM
A PCB going conductive certainly does sound nasty. It LOOKS fine and I've given it a scrub with a tooth-brush.
As soon as the set had warmed up to the point of playing there was a voltage drop of 229V across C48 and 198V across C47. By the time it started to sound really ropey these had dropped to 198V and 185V.
I've tried changing each of these for the new one and used the each of the old ones with this. It did seem to lower the initial hum but the distortion and voltages are about the same. It certainly seems worth getting another new capacitor to try. The only bogey is the 'bus fare going to fetch one but I'll be out and about in a couple of weeks so can get one then.
If it is this heather-cathode short shall I get it 'round the back of the computer monitor and "Crack it one with the EHT?" It could well be that as it does get worse as it warms up.
I'll keep fiddling and report and changes.
Thanks again for the help so far, lads.
All the best
Joe
As soon as the set had warmed up to the point of playing there was a voltage drop of 229V across C48 and 198V across C47. By the time it started to sound really ropey these had dropped to 198V and 185V.
I've tried changing each of these for the new one and used the each of the old ones with this. It did seem to lower the initial hum but the distortion and voltages are about the same. It certainly seems worth getting another new capacitor to try. The only bogey is the 'bus fare going to fetch one but I'll be out and about in a couple of weeks so can get one then.
If it is this heather-cathode short shall I get it 'round the back of the computer monitor and "Crack it one with the EHT?" It could well be that as it does get worse as it warms up.
I'll keep fiddling and report and changes.
Thanks again for the help so far, lads.
All the best
Joe
