If your 3el 40m F.S. sounds like a fantastic beam however if it had tiny
Cushcraft loading coils you probably would not refer to it as a flame
thrower:)
The Moxon is a great design and it eliminates the low-Q CC coils. I am not
sure what issues there are installing Moxon elements on a tower or mast. If
I recall correctly it is also resonant on 10m which may cause some
interaction issues.
John KK9A
-----Original Message-----
From: Grant Saviers [mailto:grants2@pacbell.net]
Sent: Tuesday, March 06, 2018 7:36 PM
To: john@kk9a.com; towertalk@contesting.com
Subject: Re: [TowerTalk] add a 3rd el to 40-2cd
Kostas,
As others have said, it is all about boom length with 3 elements. I built a
W6NL Moxon (scratch design) and have a custom 3L full size 40m on a 48'
boom. Moxon is at 92', 3L at 140'. Needless to say, the 3L is a mighty
"flamethrower" vs the Moxon, hardly a sensible comparison, height, boom
length, extra element. F/B and F/S with the 3L is quite a bit better,
listening A/B. My Moxon is a very good antenna, the full size 3 element is
a great antenna. In some contests the Moxon covers the USA and the 3L is
pointed at the DX opening.
From what you have, building the strengthened K3LR version of the W6NL
Cushcraft/Moxon is a straightforward and proven way to get a very good
antenna.
Grant KZ1W
On 3/6/2018 13:57 PM, john@kk9a.com wrote:
> I have OptiBeam 40m antennas and when playing with a model, adding an
> element really did very little. I do not recall the details but I
> think some things like SWR bandwidth were even worse. You are probably
> better off using the aluminum to make a Moxon
>
> John KK9A
>
>
>
> From: kostas sv1dpi
>
> In my club we have a Cushcraft 40-2cd antenna. We are very satisfied
> with this antenna. Recently, one of our members, donated us a second
> 40-2cd. We have not a tall tower to put them in phase (the antenna now
> is at 22m-72ft). We made a thought to shrink a little the reflector of
> the 2nd antenna and use it as director in a 3el configuration. Do you
> think that it will work? Can anyone to make a model and tell me what
> is the new length of the boom and in what position we need to put the
> elements to have 50 Ohms and finally which is the gain?
>
> On behalf of SZ1A
>
> 73 Kostas SV1DPI
>
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>
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