[Elecraft] Front end RF overload

[Michael Carter]

John, KK9A is absolutely correct: without
external bandpass filters, the replacement
of PIN diodes in the T/R switches, even with
more robust replacement devices, may not
prevent the burnout from re-occurring.

The K3/K3s lowpass filter for 15/17 meters would
offer virtually no attenuation of a high level
20 meter signal before it hits the T/R switch
diodes.

If external bandpass filters were in use, you
will want to measure the low side attenuation
of your 15 meter bandpass filter - it may not
be sufficient to prevent a high power 20 meter
signal from impinging on those T/R switch diodes.

Mike, K8CN