20-04-2015, 04:05 PM
(17-04-2015, 08:44 PM)Yorkie Wrote: When you say 'the burnt cap' do bear in mind that if it's the mains input filter, if it's across the mains, it must be a class X one, or if its from line and/or neutral it must be Class Y. If you don't have the correct cap, you can remove the filter cap completely - it has no bearing on the performance of the set. The other cap that must be changed is the audio coupling cap to the grid of the output valve. (It would help if you mentioned the model number).
Every success with the restoration!
I've just managed to buy some film caps from Maplin. These items can be found at Maplins if you streamline a search so hopefully I now have something that can be used. I think the 0.01 mFD cap is rated at over 1000 volts and it will go exactly between chassis ground and the positive lead of the large reservoir capacitor. The wax one I removed must have been very close to shorting out and is a sticky mess. The fact is almost blew the very day I took the chassis out is perhaps another classic case of sod's law.
I also have a few 0.01 bypass caps and a couple of 0.05's but I tend to replace caps in small stages so I don't get mixed up. When I have fitted these I'll go back and buy some more to be fitted.
It seems lately my soldering has picked up a bit and I've learned not to try and use too thick a wire.
It won't be that long and I'll be able to consider powering up the radio again but only after many careful tests. It seems Maplins don't have a Variac but they did have a Europe/USA converter that was cheap and it would give me 120 volts A.C. My multimeter wouldn't hold a current monitoring process and would probably blow but I know I need an Avometer as well.
I won't be rushing anyway and am very keen not to make a mess of this project. I'll need to very carefully make good connections of the filter cap and I removed the output transformer, ready to solder a filter cap to it as well and I replaced the speaker wires (the speaker has a very small tear, actually).
