Date: Sun, 21 Nov 2010 17:31:52 -0800
From: Dan Hearn <n5ardxcc@gmail.com>
Subject: Re: [TowerTalk] Hygain Hy-Tower
If you are thinking about electrical effects what is your concern?That the
Hytower will affect your Yagi or that the tower will affect the Hytower. The
Hytower is vertically polarized on all bands. On 80 I see no problem. On 20
it is resonant but it is a lousy antenna because it is 3/4 wavelength long
and a cloud warmer. I would remove the 20m stub on it.
The Hytower is quite narrow band on 80 due to its capacitive shunt
loading and only 52 foot height. I would connect the tubing whip to the top
of the tower electrically and extend it in length to restore resonance. It
will then be much broader banded and allow you to work both CW and SSB. with
reasonable SWR. I have made that mod to all of my Hytowers.
73, Dan, N5AR
### I had a full size 40m GP on top of my 1st home back in 1979...with 60 x
radials
all over the roof. Spent hrs machining and drilling out this AL plate, that it
all sat on.
I was 400 miles north of where I am now, and working 40m ssb into EU, with
just 100,
was fairly easy, on a nightly basis. In the spring of 1980, The new tower
went up...in
20' sections. The 1st 4' wass embedded in concrete, so 16' above the grnd.
Once the
2nd 20' went up, the tower was now 36' tall......and swr /performance of my
40m GP
went straight to hell ! I added another 20', and up to 56'...and 40m swr
back to normal,
BUT performance was still lousy. Added the last 20'..and now up to 76'... and
40m swr is
still ok.. but 40m performance was bad.
## I think the 40m GP and the tower were aprx 26-30' apart. I fear ur 60'
rohn + mosely
will self resonate on 80m [or close to it].....and will screw up the 80m
performance of the
hytower. Dunno if ur proposal could be modeled or not. You might end up
ok...swr wise,
but the 80m performance may be less than optimum. If you can manage it, either
locate the
hy-tower as far away from the rohn as possible.... Or use the 60' rohn tower
+ mosely, as a
shunt fed vertical on 80m. A 1/4 wave sloper off the top of the tower, would
also work superb
on 80m, and would be my 1st choice. That puts the hi current point at the top
of the tower...where
it belongs.
later......... Jim VE7RF
On Sat, Nov 20, 2010 at 6:32 PM, Larry Boekeloo <lboekeloo@sbcglobal.net>wrote:
> Does anyone have an idea of how far apart a Hygain Hy-tower would need to
> be from my 60 foot Rohn with a Mosley Pro67?
>
> I'm looking at purchasing a used hytower for some 80 dx work.
>
> Thanks.
>
> Larry, KN8N
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