[Elecraft] Efficiency of MFJ remotely-tuned loop antennas

[Andy Durbin]

A couple of people expressed an interest so here is a link to a presentation on my mag loop.   It's a while since the presentation was given but the loop is still in service in the gamma match configuration.

https://www.dropbox.com/s/5va4ygzbd410le4/Prototype%20Magnetic%20Loop%20rev%20-.pdf?dl=0

Andy, k3wyc

________________________________
From: Andy Durbin
Sent: Tuesday, January 19, 2021 5:39 PM
To: elecraft at mailman.qth.net <elecraft at mailman.qth.net>
Subject: Efficiency of MFJ remotely-tuned loop antennas

"although I saw a design not long ago that used two coaxial copper pipes with a PVC pipe as the insulator.  The inside conductor was mounted to a long threaded rod moving it in and out of the outer conductor."

Not my original idea but that's what I have on my loop (PEX insulator not PVC).  Works fine up to 100 W on 30 m but has SWR runaway at 150 W.   Capacitor is driven by a geared DC motor and is tuned from the shack.  Home brew is far more fun than buying commercial.

I'll post a link to a presentation if there is any interest.

Andy, k3wyc