I have JK Mid Tri 40 at 100'. I adjusted it at the 5 ft level for
resonance as in the manual (200 KHz down), and the resonance turned too low
at 7.020. SWR is about 2:1 at 7.1 and 3:1 on 7.2. But I am working DX on
40m SSB that I have not heard of on dipoles, and I can keep a frequency
around 7.2 when contesting.
I was excited by Jk's Moxon because of low SWR across all of 40m but low
SWR maybe it's only virtue. A minus of 2 el beams is that they lose gain
and F/B with frequency. Based on Cebik's simulation, Moxon does the same.
Ignacy, NO9E
On Wed, Oct 21, 2020 at 11:23 AM Bill via TowerTalk <
towertalk@contesting.com> wrote:
> In the process of what to do about 40 meters at my new location and I have
> a few questions for the group. I will have one 126 or 136 foot tower (Rohn
> 55 with Phillystran guys. Plans are to stack two 2 2-element Yagis. I've
> narrowed it down to the Cushcraft XM-240 and the JK mid-tri 40. Realize
> they are two different approaches to the issue but I have lots of
> different ways to go. What I am concerned about ...
> First, I have spoken to Ken at JK and he assures me we can get less than
> 2:1 SWR from 7.0 to 7.2. The Cushcraft's info says 250kHz for the XM240.
> I'm curious as to other's experiences with either antenna as far as
> structural integrity, band width, performance, any issues etc. Also
> wondering if anyone has stacked these and what effect it had on the SWR
> curve.
> Thanks for the help.
> Bill K4XS
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|