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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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26th Nov 2020, 11:48 am | #1 |
Triode
Join Date: Oct 2020
Location: Tranent, East Lothian, Scotland, UK.
Posts: 17
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Suitable replacement capacitor?
I'm thinking that while I've got my Bush VHF102 radio apart, I might as well replace the electrolytic caps, since these will be about fifty years old now. I can find straightforward replacements for most (there aren't many), but am just needing some advice on a suitable replacement for this big 3000μF cap. It's cap 56 on the left hand side in the attached circuit diagram, coupling ground to the output from the rectifier. I've found 35V 3000μF caps, but not one rated at 30V. Would a 35V cap be OK? Any advice gratefully appreciated! Many thanks...
Chris |
26th Nov 2020, 11:53 am | #2 |
Octode
Join Date: Jan 2004
Location: Southport, Merseyside, UK.
Posts: 1,156
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Re: Suitable replacement?
Yes a 35V capacitor would be fine.
John |
27th Nov 2020, 7:12 am | #3 |
Dekatron
Join Date: Jul 2009
Location: Sleaford, Lincs. UK.
Posts: 7,662
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Re: Suitable replacement capacitor?
A 35v 3300u cap would be easier to find possibly.
Andy.
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Curiosity hasn't killed this cat...so far. |
27th Nov 2020, 10:50 am | #4 |
Dekatron
Join Date: Apr 2019
Location: Worthing, West Sussex, UK.
Posts: 6,603
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Re: Suitable replacement capacitor?
As you may know Chris, a modern electrolytic will be quite a bit smaller in physical size, (even at 3,300uF/35V) compared to the original, which is fine.
David |
27th Nov 2020, 11:58 am | #5 |
Nonode
Join Date: May 2016
Location: Cornwall, UK.
Posts: 2,335
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Re: Suitable replacement capacitor?
I'd leave them if nothing's failed, and it's operating within spec. While beyond their expected design life, it's not a given that the capacitors are out of spec. A blanket 're-cap' as has become popular in America, can create problems that weren't there before. At least retain any you take out and test them (whatever equipment you have - resistance; multimeter with capacitance reading, component tester and/or a leakage tester) so you can understand why a certain capacitor's condition could cause certain symptoms. My Mayflower II is almost all original, while I had to replace a couple of decoupling capacitors on my Ferrograph when it started motorboating.
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27th Nov 2020, 4:55 pm | #6 |
Triode
Join Date: Oct 2020
Location: Tranent, East Lothian, Scotland, UK.
Posts: 17
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Re: Suitable replacement capacitor?
Many thanks for the advice and suggestions...that's all very helpful...
Chris |