Quote:
Originally Posted by FrankSinatra
Have not done anything with capacitors, have read lots of conflicting opinions on that in what best to do.
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There are indeed conflicting opinions, but on the advisability of replacing certain capacitors, you will find there is a lot of agreement.
If you don't replace the critical capacitors, then you are risking damage that is expensive and often involves parts which are no longer available.
If you don't replace the non-critical parts, then failure isn't too expensive and only involves easily sourced parts. Inconvenient, but not devastating.
Good quality capacitors are cheap, so if you replace any unnecessarily, then the wastage of money is small.
So you need to find out which are the critical capacitors in order to evade an expensive failure.
In a radio section of a radiogram, or just a plain radio there are a number of capacitors which don't usually give much trouble, but if changed, the set will need realignment to get it back to proper performance. File these as parts which experienced engineer leave alone. It's cheap in parts but expensive in time to replace them and there isn't likely to be any reliability issue with them. Some of these are mica dielectric parts with an overall wax coating. These are usually flat in shape. They are fine, unlike the cylindrical paper 'waxies'
There are certain brands and series of capacitors which are worth replacing on sight if you want the set to be reliable.
Hunts Mouldseals
Paper in wax (Waxies)
Plessey Red and Black electrolytics
are the main ones to be going on with.
Electrolytic capacitors in general are worth a quick test with an ESR meter to see if they are still OK.
There is no one-size-fits-all answer to this issue, but you should now be aware of the factors pulling you in different directions.
David