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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>>
>
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