[Elecraft] K3 , KPA500, KPA500 interaction.

[Dick Dievendorff]

As others have said, the mechanism the KAT500 uses to inhibit the amplifier is the amplifier key line, sometimes labeled PTT. The KAT500 manual shows cabling diagrams that cause the K3 key line to go thru a relay in the KAT50o to the amp.  The amp doesn't change to standby, it is simply not keyed and therefore does not amplify during ATU tuning operations. 

73 de Dick, K6KR

On Mar 16, 2013, at 6:17 PM, Bill Wiehe <bw396ss at yahoo.com> wrote:

> 
> 
> As a follow up the recent information passed along on the subject under another thread (* on KPA500) I am looking for some additional clarification. I was under the impression that
> KPA500 would go into standby automatically when the KAT500 went into a tune mode.
> Apparently this is not the case unless I have something set wrong. I have found
> when changing bands if I initiate the K3 “tune cycle” the KPA500 will not go into
> standby.The KPA500 goes in and out of transmit mode and eventually will go into a "soft fault" if there is an initially high (SWR) while the KAT500 continues to look for a match. The fault due to high reflected power of course is as it should be and must be cleared to proceed. Just curious but is this correct expectation or is there a
> set up function I missed that automatically places the KPA500 in standby  when the   As I said I was under the impression that whenever
> the KAT500 did a tune the KAP500 would go into standby.  
> This is not a major problem as I have set up the KPA500 now
> to go to standby whenever I change bands as well as initial start-up. I am still curious however if I missed something.
> Thanks
> 
> Bill – W0BBI
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