Quote:
Originally Posted by turretslug
Sorry Ben, I've just re-read your first post and I now realise that the two big blue LCR capacitors were being used as HT filter caps, rather than mains bypass- I was misled by the blue and brown wires. That's not so mad after all- one thing to beware of is that the off-load/initial switch-on HT can be far higher than the running HT. In particular, pre-war sets very often had a fast-heating directly-heated rectifier with a high forward voltage drop and a high-resistance smoothing network- this can result in an HT supply of a typical 250V or so being double that for 20 seconds or so until the other valves have warmed up. 500V is right on the limit of mainstream electrolytic capacitor voltage availability, so the previous repairer may have chosen the big LCR motor run types with good reason, these types usually have their AC voltage rating printed on them, but a DC voltage rating of typically around 630V somewhere in the spec. sheet.
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The motor run caps were 440V so I have ordered some 500V electrolytics to replace them which look to be about half the size too.
These were indeed not easy to find but are now in transit
