[Kenwood] PS-430 troubleshooting

[Dr. Gerald N. Johnson, electrical engineer]

Adding the fan seems like a good option. I don't think that is the
problem the original poster has with hum on the output, even a
relatively light loads.

I don't have a PS-430, I don't plan to ever have one. I build my own
supplies, my present supply is linear but at 22 amps load the AC watts
input (measured with true wattmeter) in is just 352 watts (85%
efficiency). It uses a relatively low voltage power transformer, 12
volts each side of center and power MOSFETs for regulation so no emitter
equalizing resistors are needed and the MOSFETs regulate down to about
.02 volts drop. The unloaded unregulated voltage is only 16 volts so
there's no need for a crowbar to protect the radio.

73, Jerry, K0CQ
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