Re: Efficiency of MFJ remotely-tuned loop antennas
Posted by
ANDY DURBIN on
Jan 20, 2021; 3:20am
URL: http://elecraft.85.s1.nabble.com/Efficiency-of-MFJ-remotely-tuned-loop-antennas-tp7667578p7667649.html
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=0Andy, k3wyc
________________________________
From: Andy Durbin
Sent: Tuesday, January 19, 2021 5:39 PM
To:
[hidden email] <
[hidden email]>
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
______________________________________________________________
Elecraft mailing list
Home:
http://mailman.qth.net/mailman/listinfo/elecraftHelp:
http://mailman.qth.net/mmfaq.htmPost: mailto:
[hidden email]
This list hosted by:
http://www.qsl.netPlease help support this email list:
http://www.qsl.net/donate.htmlMessage delivered to
[hidden email]