Bush AC 31 capacitors replacement? - UK Vintage Radio Repair and Restoration Discussion Forum

murphy512 · 28th Mar 2024, 11:31 pm

Hello,
I am working on what was a dead Bush radio.
The on/off and waveband switches were not making good contact and after sorting them out, the radio is working well.
All voltages are spot on and there is no voltage at all on the grid of V3.
Should I then change the waxies or should I leave them since the radio is working very well and looking original?
Aldo

60 oldjohn · 29th Mar 2024, 12:00 am

Hi Aldo, I would definitely change C20 & C21 Audio coupling and Tone correction caps (Trader sheet numbers) as for the others it is up to you if the HT smoothing caps have reformed ok. Depends on how much you intend using the set.
John.

Ed_Dinning · 29th Mar 2024, 6:48 am

Hi Aldo, it is also worth changing the AVC decoupling caps which may increase sensitivity.
Even a slight leak here can reduce gain, but will cause no damage

Ed

murphy512 · 29th Mar 2024, 6:11 pm

Thank you for your suggestions.
As we are only talking about a couple of capacitors then I may restuff them so the radio will still look original.
Aldo

28th Mar 2024, 11:31 pm	#1
murphy512 Pentode Join Date: Mar 2008 Location: London, UK. Posts: 122	Bush AC 31 capacitors replacement? Hello, I am working on what was a dead Bush radio. The on/off and waveband switches were not making good contact and after sorting them out, the radio is working well. All voltages are spot on and there is no voltage at all on the grid of V3. Should I then change the waxies or should I leave them since the radio is working very well and looking original? Aldo

29th Mar 2024, 12:00 am	#2
60 oldjohn Dekatron Join Date: Dec 2004 Location: East Yorkshire, UK. Posts: 3,990	Re: Bush AC 31 capacitors replacement? Hi Aldo, I would definitely change C20 & C21 Audio coupling and Tone correction caps (Trader sheet numbers) as for the others it is up to you if the HT smoothing caps have reformed ok. Depends on how much you intend using the set. John. __________________ My favourite text message "I'll be there in five minutes, if not read again"

29th Mar 2024, 6:48 am	#3
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,196	Re: Bush AC 31 capacitors replacement? Hi Aldo, it is also worth changing the AVC decoupling caps which may increase sensitivity. Even a slight leak here can reduce gain, but will cause no damage Ed

29th Mar 2024, 6:11 pm	#4
murphy512 Pentode Join Date: Mar 2008 Location: London, UK. Posts: 122	Re: Bush AC 31 capacitors replacement? Thank you for your suggestions. As we are only talking about a couple of capacitors then I may restuff them so the radio will still look original. Aldo