At 02:40 PM 2/3/00 +0000, Steve Harrison wrote:
>I gather that Larry has apparently not replaced the rectifiers as yet and
>operated the unit again. So perhaps something DID blow, taking out the
>diodes, which he will discover when he tries to fire it up again. I would
>say it would be worthwhile installing new diodes and at least getting the
>tube back into idling current again just to see whether something else
>actually has gone away. He could do this with smaller fuses than required
>for full-power operation to limit the decibels and shrapnel of a possible
>immediate Big Bang. Even a hi-pot tester would give some indication of a
>problem, particularly with the tube filament off. Perhaps the filter
>capacitor broke down; the peak voltage with capacitor input filter is about
>1.2 times the average DC output voltage; so a filter cap operated near its
>max average DC voltage rating might have been overstressed by a
>relatively-small and unnoticed AC line transient once too many times.
>
>73, Steve K0XP
Ah, the joys of modular amplifiers! It only took two minutes to jack in the
"old" supply and check out all the RF and control stuff. All as it should
be. Each component in the "new" supply was individually checked and only
the one diode leg was found broken.
Larry - W7IUV
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