[Amps] AL-1200

Vic Rosenthal 4X6GP/K2VCO k2vco.vic at gmail.com
Wed Dec 24 13:23:09 EST 2014


Make sure the primary of the plate transformer is correctly wired for 
the line voltage. For example, if the transformer is wired for 220 and 
the line voltage is 250 (not uncommon), a nominal 3200V DC across the 
caps could exceed 3600. The AL82 uses 8 450V capacitors in series for a 
total of 3600V.

This gives you no safety factor. If the bleeder resistors and/or 
capacitor values aren't evenly matched, some voltage ratings will be 
exceeded.

On 24 Dec 2014 19:51, Bob Gibson via Amps wrote:
> I'm having a problem with a friends al-1200 amp.. He is 80 years old
> I'm 71 and we can not figure this out.. I have replaced the stock P/S
> board twice.. after a short time it blows out.. I have replaced it
> now with a WD7S HV board and again it blows the caps.. I have
> replaced the step-start board with a W7RY board.. still samething.. I
> headed back up to try to work on this thing again this weekend.. any
> ideas would sure help out..Bob W5RG  Almost 60 years in Ham Radio


-- 
73,
Vic, 4X6GP/K2VCO
Rehovot, Israel
http://www.qsl.net/k2vco/


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