KPA500 tolerance
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Hello
A friend of of mine has problems with a solid state amplifier that switches to safety at the least value of SWR, like 1.2 or 1.4 ! He would like to know what is the KPA500 tolerance concerning SWR... Any idea welcome Jacques de F9OJ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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On 6/29/2011 7:43 AM, jgaudron wrote:
> A friend of of mine has problems with a solid state amplifier that switches > to safety at the least value of SWR, like 1.2 or 1.4 ! > He would like to know what is the KPA500 tolerance concerning SWR. My KPA500 puts out 600W - 675W (I've seen occasional peaks of 700W without faulting) into a reasonably matched load on the HF bands (1.5:1 or better), and 560W on 6M into a load of about 1.4:1. If the match gets to about 2:1 on the HF bands, it might fall back to 500-550w. No issues with nuisance faulting. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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I can confirm Jims findings also....1.8:1 is fine here also.
Gary On 30 June 2011 04:12, Jim Brown <[hidden email]> wrote: > On 6/29/2011 7:43 AM, jgaudron wrote: > > A friend of of mine has problems with a solid state amplifier that > switches > > to safety at the least value of SWR, like 1.2 or 1.4 ! > > He would like to know what is the KPA500 tolerance concerning SWR. > > My KPA500 puts out 600W - 675W (I've seen occasional peaks of 700W > without faulting) into a reasonably matched load on the HF bands (1.5:1 > or better), and 560W on 6M into a load of about 1.4:1. If the match > gets to about 2:1 on the HF bands, it might fall back to 500-550w. No > issues with nuisance faulting. > > 73, Jim K9YC > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > -- VK4FD - Motorhome Mobile Elecraft Equipment K3 #679, KPA-500 #018 Living the dream!!! ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Dear All,
The below mail also be of interest: -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Eric Swartz - WA6HHQ, Elecraft Sent: 11. maj 2011 20:10 To: Geoffrey Downs Cc: [hidden email] Subject: Re: [Elecraft] KPA500 and SWR above 1.5:1 The KPA500 bases its SWR protection on reflected power level, not an absolute SWR. The KPA500 is happy up to a 2:1 SWR at 500-W out. As long as the actual reflected power is below that for a 2:1 SWR at 500W, it will not reduce its power. This means you can operate into a higher than 2:1 SWR load at full amplifier gain if you reduce the amp's output power slightly. The amp "soft-faults" and reduces output power by about 2.5 dB by switching in an input attenuator at the 500W 2:1 reflected power point, and it flashes a red LED to alert you to this so you can adjust driver power (or SWR via an external tuner) down a bit. Once this is corrected below this threshold by the operator, the KPA500 automatically goes back to full gain. It also does this for minor overdrive conditions. Of course, for excessive SWR events (wrong antenna, open antenna etc), and severe overdrive, the amp protects itself by immediately hard faulting and going into bypass mode. After correcting the fault, just push the operate/standby switch to get back on-line. While at Contest University, our Italian representative surprised me by demonstrating this feature to customers by pulling the coax from the dummy load while the amp was transmitting. After I recovered from my surprise, I realized the amp was perfectly happy and had protected itself as advertised :-) But don't try this at home, as he also received a minor RF burn to help him remember this event.. 73, Eric WA6HHQ www.elecraft.com ==== ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Gary Gregory Sent: 30. juni 2011 08:31 To: [hidden email] Cc: [hidden email] Subject: Re: [Elecraft] KPA500 tolerance I can confirm Jims findings also....1.8:1 is fine here also. Gary On 30 June 2011 04:12, Jim Brown <[hidden email]> wrote: > On 6/29/2011 7:43 AM, jgaudron wrote: > > A friend of of mine has problems with a solid state amplifier that > switches > > to safety at the least value of SWR, like 1.2 or 1.4 ! > > He would like to know what is the KPA500 tolerance concerning SWR. > > My KPA500 puts out 600W - 675W (I've seen occasional peaks of 700W > without faulting) into a reasonably matched load on the HF bands > (1.5:1 or better), and 560W on 6M into a load of about 1.4:1. If the match > gets to about 2:1 on the HF bands, it might fall back to 500-550w. No > issues with nuisance faulting. > > 73, Jim K9YC > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html > -- VK4FD - Motorhome Mobile Elecraft Equipment K3 #679, KPA-500 #018 Living the dream!!! ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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