[Elecraft] KPA1500 Faulting for High SWR inappropriately

[Hal Massey]

Merry Christmas! Make sure it is not a transient antenna condition. A solid state amp is going to detect faults rather quickly. A lot of a log SWR/Wattmeters may not see these same faults…. 

> On Dec 19, 2022, at 8:51 PM, Jack Brindle via Elecraft <elecraft at mailman.qth.net> wrote:
> 
> What is the fault? We see a lot of issues with antenna systems not being able to handle the higher power, either 500 or 1500 watts. This can develop over time or show up very quickly after the amp is installed. Be sure to check the cabling and connectors for possible arcing.
> In this situation, things would work just fine at low power, but not at high power, with the exact symptoms  you describe.
> 
> 
> 73,
> Jack, W6FB
> 
> 
>> On Dec 19, 2022, at 3:58 PM, David F. Reed <w5sv.dave at gmail.com <mailto:w5sv.dave at gmail.com>> wrote:
>> 
>> Lou,
>> 
>> I appreciate the suggestion, but it is with a K4D, properly cabled, used to work fine, and does it on some bands but not others... changed the delay to 15ms and still does it... Also seems to depend on band; for example, does it on 10m, not on 12m...
>> 
>> Also, below, I said 2 SWR meters; I meant 3...
>> 
>> 73 de Dave, W5SV
>> 
>> On 19-12-22 21:28, Lou Laderman wrote:
>>> Check the delay setting on your transmitter. You might have a hot switching issue. I think (but check your manual) that unless you’re using the KPA1500 with a K3 or K4 without the 15-pin Elecraft interface cable, you’ll want at least 10ms of delay to avoid that. I had that issue with a K4 and a PGXL. Default on the K4 is 8ms and the PGXL needed 10ms.
>>> 
>>> 73, Lou W0FK
>>> 
>>> Lou Laderman
>>> Sent from my mobile device
>>> 
>>> On Dec 19, 2022, at 2:59 PM, David F. Reed <w5sv.dave at gmail.com> wrote:
>>> 
>>> My KPA1500 has started faulting inappropriately for High SWR.
>>> 
>>> I say inappropriately because all 2 of my SWR meters (K4D, KPA1500, Palstar HF-AUTO) show an SWR of between 1.1:1 and 1.2:1. with just the K$ transmitting and also with the KPA1500 in fine as it faults out.
>>> 
>>> Any ideas?
>>> 
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft at mailman.qth.net
>> 
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to jackbrindle at me.com <mailto:jackbrindle at me.com>
> 
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net <http://www.qsl.net/>
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to haljr.massey at gmail.com <mailto:haljr.massey at gmail.com>