[TowerTalk] Hygain Hy-Tower

[Jim Thomson]

Date: Sun, 21 Nov 2010 17:31:52 -0800
From: Dan Hearn <n5ardxcc at 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 at 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