17-04-2015, 05:18 PM
(17-04-2015, 04:39 PM)Refugee Wrote: The actual values of those capacitors are not critical and the voltage just has to be greater than the battery voltage.
160uf use 220uf 25 volt
50uf use 47uf 25 volt
30uf use 33uf 25 volt
We are not yet sure the transistor is faulty just yet as it was measured in circuit and the biasing resistors will have produced false readings.
Thanks. I popped back to Maplins just and now have the caps. Only snag is they're not film ones so polarity may be an issue - that is I'll have to be sure they're fitted pos and neg. The ones I removed had a centre and side lead and I did jot down a few notes.
I bought a PNP transistor just in case while I was at the store. The original transistor is indeed fine as I resoldered some fine wire back to the leads and it seems fairly robust. I will probably put it back in situ.
I forgot to say, by the way, I noticed one capacitor was puffed at the top so it now seems an electrolytic was knackered. It could well be the case that the cap went kind of wild as I was attempting to fire up the radio and it all led to heating of the speaker. It could even be the case it was nothing I did wrong but the cap was just a weak link so I got a burst of stations coming in and then fading out.
Anyway, I'm very appreciative of all the terrific advice you guys hand out here and will keep plodding on with a possible hope of a future fix. Keeps me away from the DVD movies.
