Mark, when you tune your amp you are reading the input impedance of the amp SWR, not the antenna SWR. The only way that your external SWR meter and the transceiver SWR meter should match is if the external meter is between the amp and the transceiver. Even then, the SWR meters available to us are not precision instruments and are usually 5 to 10% of the max reading, so a 2kw watt meter could read 200 watts in error and still be in tolerance for an inexpensive meter. The better meters could be 100 watts in error, so the error can equal or exceed the output of the transceiver. If the 1.6 bothers you, you can adjust the input impedance matching circuit of the amplifier and perhaps reduce it, or you can activate your antenna tuner on your transceiver if you have one. You can also expect the SWR to change some as you tune your amp. If you have an old amp from the tube final days when the transceivers all had a pi network to match the amp, such as my Dentron Clipperton L, you may not even have an input matching circuit. I use the tuner in my K3 to match the input of the Clipperton. I don[t think you have anything to worry about. Willis 'Cookie' Cooke K5EWJ
________________________________ From: "[email protected]" <[email protected]> To: [email protected] Sent: Mon, November 15, 2010 5:43:49 AM Subject: [Elecraft] Higher SWR When Using Amp. I have noticed when I fired up my amplifier on 40 meters that the SWR reading on the K3 when I tune up is higher then when I tune up on standby. But what is really odd is on my External Wattmeter the SWR is the same when the amp is active versus standby. On standby my SWR on 40 meter SSB is 1.0 to 1. When I tune the Amp it goes up to 1.6 to 1. I realize that it isn't that high but just would like to know if there is an explanation as to why this occurs. Mark KB3Z ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] 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:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
