Towertalk
[Top] [All Lists]

[TowerTalk] N6AW on 30m BIG GUN SIGNAL

To: <towertalk@contesting.com>
Subject: [TowerTalk] N6AW on 30m BIG GUN SIGNAL
From: w8ji.tom@MCIONE.com (w8ji.tom)
Date: Mon, 19 Oct 1998 09:46:17 -0400
Hi Josh,

You wrote:
> The other night I heard someone working
> Europeans and Russians on 30m 
> Most of the DX I could barely hear !!
> He said that he was using a Rhombic  350 meters
> in over- all length  aiming Europe.
> HE was putting out an absolutely awesome signal !! with 200 watts!
> getting 599   from ZS6QU   off the side.

Of course I can't say if what you heard was "real or Memorex", but I'm
skeptical about antennas provide exceptional gain in all directions at all
distances.

A Rhombic 350 meters on a side (11 wavelengths) would have a fairly narrow
main lobe. Unless Russia is almost in line with England from W6, it would
be too narrow to cover both.

Gain would be about 12-15 dBd in the main lobe, because the
antenna "gain limits" at about 3 or 4 wavelengths per leg.

Also consider that having a "booming signal" off the side means a lot of
energy was not available in the main lobe. How can an antenna have high
gain and super performance in every direction? Does that make sense?

> Can  Rhombics be effective with Metal supports?

Sure. 

> I always here about the tall telephone poles supporting Rhombics?

It would have to be a tall pole! Rhombics, to minimize earth losses, need
to be at least 1/3 their leg length above earth. 

The main advantage of a Rhombic is the very wide useable bandwidth. If you
want gain, there are much more real estate friendly ways of doing it.

73 Tom

--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm


<Prev in Thread] Current Thread [Next in Thread>