Art KY1K wrote:
When I joined the list, it was to get the skinny on solid state amps,
little did I realize that my tube type amp would die and I'd be
consulting the list for hV diode suggestions and vendors.
But:
I have a bottom end amp, 400 watts out, an AL84. The plate voltage
dropped from just under 1kV (unloaded) to 600v and obviously the power
output is way down. I assume I need new rectifiers.
The manual says it uses 1kV @ 3 amp diodes, 8 of them total, in a full
wave bridge rectifier configuration. The part number is AR-145, which
isn't available, it's likely an Ameritron house number. The voltage
rating of each diode seems marginal to me though (to me).
I looked in Digikey and Mouser, they don't don't carry them.
There are no equalizing caps or resistors, so I'd prefer to put in a
single 4kV diode rather than deal with 2 diodes in each leg of the
bridge. Barring that, I'd like to replace all 8 diodes with 2kV @ 2 amp
diodes.
Are there any reputable vendors that sell these lower voltage diodes at
a reasonable price, I would prefer NOT to use the online auction site::>
Would appreciate any comments or suggestions.
Rectifiers generally don't do that without adding HUM to your signal.
I would first look into the electrolytic capacitors.
BTW: I would use 10A10 diodes* (or 10A6) if I could get them to fit,
remember one layer can be down on the PCB and intermediate diodes could
be on long leads far above the PCB between the bottom layer of diodes.
* I got mine from China via amazon.com
--
Ron KA4INM - Youvan's corollary:
Every action results in unwanted side effects.
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