[TowerTalk] Force 12 feedpoint matching coil redux

[Bryan Swadener]

What John said. My C-4XL came to me with an ugly-looking
4 turn inductor, and the instructions mentioned a 3
turn coil. I tried it as-is but, the resonant frequency
was around 6.9 MHz. I wound a new coil, and all was
well with the world.
vy 73 es gl,
Bryan WA7PRC


Date: Sun, 27 Dec 2015 11:37:39 -0500
>From: "John Santillo" <u1004467 at warwick.net>
>To: "'Howard Hoyt'" <hhoyt at mebtel.net>,    <towertalk at contesting.com>
>Subject: Re: [TowerTalk] Force 12 feedpoint matching coil redux
>
>Howie,
>
>Yes, I own a C4SXL and it is needed to provide the proper match.  
>
>My coil is 3 Turns with an inside diameter of 2.75" and the coil is made of
>solid 8 Gauge copper wire.  When my old coil fractured I used .125" copper
>tubing and that worked just fine. 
>
>
>73,
>
>John
>N2HMM
>
>
>-----Original Message-----
>From: Howard Hoyt
>Sent: Sunday, December 27, 2015 10:58 AM
>To: towertalk at contesting.com
>Subject: [TowerTalk] Force 12 feedpoint matching coil redux
>
>Hi TowerTalk braintrust,
>
>Can owners of the Force12 EF240S / C4SXL tell me if the 3T loading coil is
>needed on the 40M driver feedpoint for a proper match?  In the manual it
>calls out one, but the used antenna I got had that coil cut off.  I
>contacted Force12 and asked them for the specs of the coil so I could make
>one but they said they would have to research it and I've not heard back.
>
>I considered trying to model it in EZNEC, but I can't physically measure the
>linear loading section because  mine is taken apart. Does anyone have an
>EZNEC model of the C-4SXL/EF240S... to share?
>
>Cheers & 73,
>
>Howie - WA4PSC