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Re: [TowerTalk] Force12 EF-320

To: "" <>
Subject: Re: [TowerTalk] Force12 EF-320
From: Tom_N2SR via TowerTalk <>
Reply-to: Tom_N2SR <>
Date: Mon, 8 Aug 2016 16:54:29 +0000 (UTC)
List-post: <">>
While I do not have the antenna, I do have a pair of C31XRs, which I think the 
EF-320 design is implemented into the C31XR's design.   
On 20m, the C31XR uses a 5T 2.0" 0.125" hard drawn copper coil across the 
With a W0IYH (?), RG-393 (?) with 100 beads, I have a FLAT VSWR across the 
entire band on both antennas.  The VSWR is no higher than 1.4:1 anywhere.   
Tom, N2SR

      From: Wayne Kline <>
 To: "" <>; "" 
 Sent: Monday, August 8, 2016 8:33 AM
 Subject: Re: [TowerTalk] Force12 EF-320
To add to John's replay.  I have no experience with the  EF-320 but do on many 
of there other antenna models. So are OWA 50 ohm direct feed some are not....  
Not sure of your antenna.A quick  visual examination can tell if it has a Beta 
Match.  Tom N6BT  used soft  aluminum refrigeration tubing as the varying 
length loops as his impendence match.  So a quick look  will tell you if  your 
antenna has one.  As with any trouble shooting I start at one end and work my 
way to the other.  a dummy load and a few connectors you can check all your 
coax and switches out to the tower.  Then  is a clime in order  to check the 
feed line connection and the finial  end of feed line wring out...  In the past 
I have experienced  Balun F-12, failure.. I assumed it was due to close feed 
lighting strikes.....  We went to the gray box type with  RG142 wound over 
stacked cores and overcame the glitch...
Wayne  W3EA  

> Date: Mon, 8 Aug 2016 07:53:13 -0400
> From:
> To:
> Subject: Re: [TowerTalk] Force12 EF-320
> I have no experience with Force12 beams. However, since your post was
> unanswered and lost in the measuring coax loss within .001dB thread I will
> try to help. I believe that Force12 monobanders are OWA design, meaning
> that the coax is directly connected to the driven element with no matching
> to go wrong.  How high is the SWR and how are you measuring this?  If you
> have coax in multiples of 1/2 WL lengths you can also check the impedance
> with an antenna analyzer. Did you double check your measurements? Are you
> using the Force12 balun and good coax? Is there anything near the antenna
> that could be detuning it?
> John KK9A
> To:
> Subject:    [TowerTalk] Force12 EF-320
> From:    wp3c via TowerTalk <>
> Reply-to:    wp3c <>
> Date:    Sun, 07 Aug 2016 10:00:43 -0400
> Hi
> I put a Force 12 EF-315 and a EF-320.
> The one for 15M (EF-315) is 1:1 but the one for 20M (EF-320) I'm having SWR
> high.
> Did someone here that have some  knowledge about this antenna and could bring
> some help with this?
> Thanks
> Alfredo WP3C
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