I have to agree with Rich; the stock 1N5408's are fine for that amp.
I have worked on many LK-800A and -TNY versions with never a diode
problem. One thing to remember is that the 1N5408 is an industrially
rated device.
The K2AW diodes are simply Microwave Oven devices with a "new" part
number. They work fine for lots of ham use but I cant see spending $60
for 4 when a string of $ .25 1N5408's have better specs.
The biggest favor you can do for your LK-800 is to remove the filter
board and set it up so that you can measure the voltage across each
capacitor. A total variation of about 5% total is OK for the stock 100K
equalizing resistors. If it exceeds that I would suggest measuring all of
those resistors. If they are all within tolerance and the capacitor
voltage variation is high you should consider changing to 75K 3W metal
oxide resistors and remeasure. The auxiliary fan above the PS will
provide sufficient cooling.
73....Carl KM1H
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