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Old 16th Dec 2017, 4:43 pm   #20
ms660
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Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
Default Re: Alba 3112: completely disoriented

Quote:
Originally Posted by aechopan View Post
My guess for next steps would be:

-Replace that resistor for a modern one (100 Ohm, 0.25 W).
-Replace capacitors evidently leaking:
  • C31 with 0.022Uf Class X1, 440V
  • C28 with 4.7nF Mylar/Polyester, 100V
-Replace the scary mains cable made of nylon by a modern one (2-Core 3A).

Does anything sound crazy?
If you mean R24 the 0.25 watt rating won't be enough, power dissipated will be Isquared*R, which in the event of a bulb failure will be a lot higher, at least 2.5 watts or possibly more because the resistor in a failed bulb situation will be passing the heater current and the HT rectifier current, for cooler running use a 5 watt job.

C31...X2 class will be ok if you can get one.

You need to up your voltage rating for C28, 630 VDC should be ok.

Lawrence.
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