Watch out with length of coax between xcvr + input of the amp.? ? On all 4 of my Drake L4B amps, if coax is 3' long, input swr is flat on all bands.? ?But when I use a 6' jumper, input swr increases to aprx? 1.4:1? or? 1.5:1? ? and no amount of slug tuning will reduce it.? And the Q of the tuned input PI networks on the drake amps is a helluva lot higher? vs a SB-220.? (cap values are higher)
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On my big hb amps, they all use a manually tuned, PI tuned input.? Same deal, but at least I can tune it dead flat.?
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I still have not figured out why the interconnecting coax length affects? input swr.?
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Jim? ?VE7RF
