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Old 17th Sep 2019, 11:41 pm   #2
turretslug
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Join Date: Nov 2011
Location: Surrey, UK.
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Default Re: Regentone A133 HT smoothing capacitors, V4 cathode resistor

I don't know how long this set was in production for, but I wouldn't be surprised if the later ones got the 50 + 50uF (double unit?) version, probably by then the 50uF types were the same size and price as the 32uF version and the latter may even have been superceded. Electrolytics have a very wide tolerance anyway- particularly back then- often -20+50% or even -20+80% or the like, so it's not critical. Quite honestly, I'd go for "British compromise" here and make the first (reservoir) section replacement a 33uF (being kind to the rectifier) and the second (smoother) a 47uF (good hum reduction)! I'm assuming that you would be using modern separate types here, which will almost certainly be compact enough to tuck away tidily underneath.

The cathode resistor change isn't a bad idea at all- it's not often that the volume needs to be anything like maximum even in a modest radio and output valves are a diminishing resource, so wise to give it an easier time. You might even find that 270 ohms is an acceptable compromise,

Colin
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