[Elecraft] KPA-1500 Power Output Variation

[Bill Johnson]

Thank you, Jim.  That is more helpful.  I use a remote tuner rather than using the built in for matching.  Thus my situation would not match yours.  I use a 350 loop on 40 meters, thus I would not be helpful in your situation.  Using a tube amp is much different in matching versus the solid state amplifier as I remember when I last used a tube amp.  I believe your specifics will now lead to a better answer to your situation.

73,
Bill
K9YEQ

https://wrj-tech.com/

-----Original Message-----
From: elecraft-bounces at mailman.qth.net <elecraft-bounces at mailman.qth.net> On Behalf Of Jim McCook
Sent: Saturday, August 24, 2019 2:58 PM
To: Elecraft Reflector <elecraft at mailman.qth.net>
Subject: [Elecraft] KPA-1500 Power Output Variation

Antenna is 2 el. delta.  Uses 1/4 wave 70 ohm matching section. 
Described in ON4UN's Low Band DXing.  Used for 38 years with various tube amplifiers and no tuners.  All coax has been replaced as recently as 10 years ago.  SWR measurements always similar.  Power output with tube amps does not vary visibly on a Bird WM.  Same situation currently with a tube amp substituted.  Feedline from matching section about 50 ft.  I know how to match antennas.:-) I have seen the usual reactance measurement on each side of design frequency of 7.025.  The built in tuner is the one I was referencing.  The KPA-1500 comes with one.

Jim
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