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Re: [TowerTalk] JK Mid Tri opinions

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Subject: Re: [TowerTalk] JK Mid Tri opinions
From: Jeff Blaine <KeepWalking188@ac0c.com>
Date: Sun, 22 Dec 2019 21:28:24 -0600
List-post: <mailto:towertalk@contesting.com>
Are you talking about the 40m performance?  A local here K3PA has a mid-tri and has much better F/B on the higher bands but the 40m is as you say, in the 10-15 range - but that's to be expected from a conventional 2-element.

73/jeff/ac0c
alpha-charlie-zero-charlie
www.ac0c.com


On 12/22/19 9:00 PM, K9MA wrote:
I’m not sure the trade off of f/b for forward gain was deliberate, as the 
published model results show higher f/b. I am pretty sure my measurements are good. I 
did them with two other stations, one about 20 miles away and another 250 feet from my 
antenna. Both used horizontally polarized beams. Results were very close, and 
consistent with my operating experience.

I can’t measure gain, of course, but the pattern looked reasonable, so I’m not 
concerned about the f/b. It even helps sometimes, as in this area your beam is usually 
pointed the wrong way.

73,
Scott K9MA


----------

Scott Ellington

  --- via iPad

On Dec 22, 2019, at 8:18 PM, Robert Harmon <k6uj@pacbell.net> wrote:

Scott,

That sounds good Scott.  I remember asking Tom, N6BT, one time about the 
forward gain vs f/b on his Force 12 Yagis and
as I understood it he tended to scrifice a little f/b to optomize the forward 
gain.   Thats fine with me.

I have a JK 402 up now and am very happy with the JK construction.  I'm sure 
the Mid-Tri will be good also mechanically.

thanks for the info

Bob
K6UJ




On Dec 22, 2019, at 6:07 PM, K9MA <k9ma@sdellington.us> wrote:

I put one up last summer. It seems to work fine, though the f/b appears to be only 
12-15 dB. That’s not necessarily a bad thing.

The SWR looks very good measured at the shack, closely matching the published curves. 
Strangely, when I measured it up at the feedpoint, it looked different, though not 
really bad. Feedline loss is too low to explain that, so I don’t know what to 
make of it. W3JK predicted this effect.

I’ve not tried load it on 12 or 17.

73,

Scott K9MA

----------

Scott Ellington

--- via iPad

On Dec 22, 2019, at 5:15 PM, Robert Harmon <k6uj@pacbell.net> wrote:

I am thinking about getting the JK Mid Tri.
Have one ?  How well does it play ?

Also, have you tried to load it on 17 and 24 with a tuner ?
The Force 12 C31XR could be loaded on 17 and 24 with a tuner,  not that great,  
but it worked.

Bob
K6UJ



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