On 3/8/2011 3:56 AM, John wrote:
> Greetings Amplifier Aficionados!
>
> This is KX5JT. You guys may remember a year ago after acquiring a
> Henry 2K4 amplifier that I pressed into A.M. service, I had to replace
> the improperly designed toroidal filament choke. It was NOT bifilar
> wound. A bifilar wound replacement took care of the AC hum on the
> carrier.
>
> Well, one of the Eimac 3-500Z's had a sagging element and after heating
> shorted and took out a block rectifier in the P.S.
>
> SOOOO I have replacement HV block rectifiers and I have the originals
> out of the bottom of the case. HOW ON EARTH do I get those new ones in
> place and soldered in there? With the plate transformer in place, it's
> VERY tight. Am I just going to have to cram my hands in there and do
> my best to screw the back side of those rectifers in place and solder
> in that tight dark area?
It's not terribly difficult to get the 2K4 apart, but it is time
consuming and requires care. It's quite easy to scratch the paint job.
If I can find them I'll post the photos of when I completely redid the
PS in the one I had.
> I'm HOPING there is some trick to gaining better access. I see the
> entire "chassis" for the power supply is basically a steel box that
> COULD be removed from the "case" but that would be delicate and
> involved to say the least.
Mine had the PS on a 1/4 thick aluminum plate. I removed the cover on
the power supply pedestal which made access to everything in there quite
easy. The difficult part is taking the RF deck apart and getting at the
multi function switch for the multi-meter. If you tackle that, take
pictures! There's a lot of linkage in there between the front panel and
the front of the RF deck. We replaced the HV transformer with a heavy
duty Peter Dahl which required redrilling the plate.
> Removing the plate transformer itself would
> free up a lot of room but how to I access the two screws toward the
> FRONT of the amp (screwing down the plate xformer) from the back of the
> amp?
In mine there was plenty of room to reach over the transformer install
the screws using either a magnetic screwdriver or one that holds the
screw in place. IIRC those are 1" 1/4-20s.
OTOH when I had the cover off they were easy to reach directly.
73 and good luck,
Roger (K8RI)
> Pulling my hair out trying to figure out what should be simple...
>
> John KX5JT
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