I have seen higher SWR with amplifiers connected in-line but not energized. It seems I saw this in recent tests I made with my Mirage A1015G (10w/150w), so I did a quick check.

I ran 5w with the K3/10 so I could use the 5A element (25-60 MHz) in my Bird power meter and tested into a dummy load to start with.

had 1.0 SWR indicated by the K3 and zero reflected showing on the Bird with power adjusted exactly to 5w forward. Then I inserted the 6m PA and got exactly the same readings. I did see forward power shift about 0.2w so its not a perfect match.

I repeated the test with my 3-element 6m yagi as load. Straight connection shows 0.25w reflected and SWR=1.5. I got exactly the same measurements when the amp was inserted.

I would not have been surprised to see a change in readings with the antenna load since it is not a perfect match. Getting a good match is often not realized with the open frame relays that are commonly used in ham amplifiers
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While I had everything set up I decided to measure the amp output with my 100H and 500H elements. With 6w drive I found I get 100w output showing with the 100H and 110w showing with the 500H. With power set to full output of 8w 130w is displayed with the 500H element. I typically claim it will do 125w.
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Subject: Re: [Elecraft] Fw: HIgh swr on 6m
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Stewart, do you have an amplifier attached? ?I have found that having my Clipperton L in the circuit causes high SWR on 6 meters, but if I connect direct to the antenna switch the SWR on my SteppIR is low as it should be. ?
?
Willis 'Cookie' Cooke
K5EWJ & Trustee N5BPS, USS Cavalla, USS Stewart

73, Ed - KL7UW
http://www.kl7uw.com
dubus...@gmail.com
"Kits made by KL7UW"
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