Bush TR82B problems

[Mylkinut]

Hi all - brand new to the forum as well as vintage radios (please forgive my lack of knowledge!).

I recently inherited a Bush TR82B which I'm quite keen to see if I can get going and learn something new in the process. I've got some soldering skills (mostly from modding/repairing guitars). If it's not worth the effort it's no great loss - it looks quite pretty on the shelf anyway!

The current situation is this:

• It has a new battery in it

• Switches on, but only static comes through the speaker

• Volume and tone pots both seem to be functioning and reasonably crackle-free after some contact cleaner

• After switching between Med and Long repeatedly (to see how the mechanism worked, largely out of curiosity) it started picking up a station, albeit it with a fair amount of static. I couldn't move away from this station using the tuning dial - it was stuck on that station.

• That lasted about 10 minutes - in that 10 minutes it dropped out a couple of times, but switching to Long and back again kicked it back in.

• Now I can only very faintly hear voices and music, and it's almost all static.

The serial number is 345/06551 - I believe this is an earlier one without the AF117 transistors but I could be wrong.

Where should I start looking to diagnose its problems? Any help would be brilliant. I've attached some pictures if it makes things easier.

Thanks!

[Station X]

Hello and welcome to the forums.

As far as I know these sets used OC series transistors.

I'd start by applying Servisol to all the pots and switches.

I'm not normally one to advocate wholesale component replacements, but those red/yellow/black Plessey electrolytic capacitors are unreliable.

The correct approach is to measure voltages and compare them with the service sheet.

http://www.service-data.com/product.php/655/1065/m10655

[paulsherwin]

It's probably the wavechange switch contacts which tend to oxidise.

It's clear from the photos that OC44/5 transistors are fitted which are generally reliable.

[60 oldjohn]

I had one with similar fault, once the wave change switch has been cleaned, try a bit of GENTLE heat on the three black transistors OC44 / 45. in my set warming between finger and thumb would be enough for the set to burst into life.


John.

[Scottart]

I've recently restored one of these radios.
The wave change switch was horribly dirty/oxidised, but after careful cleaning ( Deoxit / IPA etc ), it now works fine.
I also replaced the Plessey red/yellow/black electrolytics - not known for their reliability.
Stephen

[Mylkinut]

Brilliant - thanks everyone for their responses! I've managed to get hold of some Servisol from my in-laws so I'll get the wave change switch cleaned up once I'm back home. Will also give warming the transistors a go.

Thanks again everyone - will update with any progress as I go!

[Keith]

Originally Posted by 60 oldjohn

I had one with similar fault, once the wave change switch has been cleaned, try a bit of GENTLE heat on the three black transistors OC44 / 45. in my set warming between finger and thumb would be enough for the set to burst into life.

Slightly off topic, but curious to know how warming Ge transistors would restore operation...

[60 oldjohn]

Hi Keith, not sure but it worked for me, and kept working until switch off. Upon turning on again it needed warmth again, and ultimately another transistor.


John.

[crackle]

I have not known these OC transistors to respond like that. I wonder if that was the real cause of it starting to work or if during the time you were "warming" the transistor a capacitor reformed enough to get the set going.

Mike