[Elecraft] Checking KPA relays

[Don Wilhelm]

Jerry,

I assume you are working on a KPA100 - if not, please ignore.
The easiest way to check the relays and the LPF of the KPA100 is with an 
antenna analyzer.
Put the KPA100 to the right of the K2 (upside down on a book or other 
support) with the ribbon cable connected to the K2.  Power only the base 
K2 through the coaxial jack.
Put the leads of a 50 (ok, 51 will do fine) ohm resistor into the 
connector that normally connects to the AUX RF header.
Power the K2 on and select each band in turn.  For each band, scan 
through the frequency range of the antenna analyzer to determine the 
cutoff frequency for the LPF - it should be higher than the band edge, 
but lower than the 2nd harmonic.
If all bands meet that criteria, the relays and LPF are correct - 
assemble the KPA100 to the base K2 and go.

73,
Don W3FPR

n0jrn wrote:
> Gang:           I'm finally off for the weekend.   Just curious, what is the 
> easiest way to check the low pass filter relays to see if they are 
> working?????
>
> I've already checked U2 and pins 13 -18 are going low as they should.  I'm 
> just not sure what I should be looking for to determine if the relays are 
> working.
>
> Thanks and 73
>
> Jerry          N0JRN 
>
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