[Elecraft] KPA500 installtion with ICOM 7300

[Jack Brindle]

Don is correct (as usual). The KPA will first see the band change, perform that task, then try to amplify at the desired frequency. If it then sees a bad reflected power level it will wait for the KAT to do something (which means removing PTT, then performing its own correction, then re-enabling PTT). If it still sees a bad reflected power level (perhaps there is no KAT), then it will start the remediation process which may end in a fault. 

Note that the KPA500 watches reflected power, not SWR (unless SWR is _really_ high). This means that at full output it will object to SWR over about 2:1, while at lower power (say 300 watts), it will allow a higher SWR. Reflected power over about 50 or 60 watts is where it starts the remediation process.That process includes inserting attenuation at the front end (which should also lower the reflected power level) and ultimately in a fault if the attenuation doesn’t do its task or the reflected power is deemed way to high to handle.

So the real answer is that unless you send CW extremely slowly, the KPA500 will perform the band switch and continue monitoring the signal during that first dit, but you probably will not see anything like a fault until many characters down the QSO.

Enjoy the KPA500!

73,
Jack, W6FB


> On May 10, 2018, at 7:20 AM, Don Wilhelm <donwilh at embarqmail.com> wrote:
> 
> John,
> 
> The amp is bypassed if the KAT500 needs do do any tuning or switching, so I suspect the amp will not fault.
> 
> That is why you run the keying line first to the KAT500 and then from the KAT500 to the KPA500, so the tuner can disable the amp.
> 
> 73,
> Don W3FPR
> 
> On 5/10/2018 9:31 AM, john at kk9a.com wrote:
>> I concur that the RF sense works very well, at least it does with an
>> external antenna switch and reasonably good antenna SWR.  I am not sure
>> what happens if you also use the KAT500 as an antenna switch or your
>> untuned SWR is very bad.  Does the amp fault during this first dit?
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