Well, I'm not surprised at all, Bill! Some years back some broadcast
engineers did a lot of work replacing deteriorated buried radial fields
under broadcast towers with elevated resonant radials. They concluded that 4
elevated radials would do the job quite well. Their work was published in
some IEEE transactions, and was based on real engineering measurements!
Your inverted L with 4 elevated resonant radial should do quite well!
73,
Charlie, K4OTV
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Bill
Stewart
Sent: Monday, January 06, 2014 7:00 PM
To: Charlie Cunningham
Cc: topband@contesting.com; Robert L Chortek
Subject: Re: Topband: Radial Question
Charlie, I was surprised at how well my Inv L/c-poise works. It is far from
an ideal situation...amongst many tall pines, but results have been very
much worth the effort. I got some good info off this list and got it tuned
up to where the TS-440S did not need a tuner to get a low SWR...and it
receives ok too. I read about how much work/$$ guys put into the radial
systems and it seems that after a point, the work just ain't worth the
fraction of a db ya get. But if it makes one feel better, then keep on
digging...hi.
73 de Bill K4JYS
----- Original Message -----
From: "Charlie Cunningham" <charlie-cunningham@nc.rr.com>
To: "Bill Stewart" <cwopr@embarqmail.com>, "Robert L Chortek"
<Robert.Chortek@berliner.com>
Cc: topband@contesting.com
Sent: Monday, January 6, 2014 5:52:50 PM
Subject: RE: Topband: Radial Question
Hi, Bill
Well, I have modeled a 160 inverted L with 4 elevated resonant radials, with
EXNEC, and that's about as good as it gets! Guys with grounded towers have
to dig and bury radials or run 'em on the ground but the broadcasters'
experience with elevated radials indicates the 4 is about as good as it gets
- adding more doesn't add much. Having the resonant radials fanned over
less than 360 degrees can produce sone asymmetry in the azimuth pattern, but
mine with two at 90 degrees worked quite well in all directions! Generally,
if I could hear 'em I could work 'em. The KAZ receiving loops helped a LOT
on receive!
73,
Charlie, K4OTV
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Bill
Stewart
Sent: Monday, January 06, 2014 5:25 PM
To: Robert L Chortek
Cc: topband@contesting.com
Subject: Re: Topband: Radial Question
Hi Bob,
I can't add much in the way of technical reasons for adding the radials vs a
c-poise. However, I can say that my Inv. L, with a four wire quarter wave
c-poise has worked quite well...and with much less work than all the radials
you are considering.
I use only 100 watts and have worked into the Carib. and the recent K9W
operation. I also have been using a HB QRP xmtr from
1924 and have worked from C6 up into VE2/VE3.
I would wonder about the possibility of 'under-the-house' radials putting rf
into your house wiring, and if using your xmit antenna for rcving, picking
up trash from your in-house gadgets...tv, computer etc, esp if you are
running power. You may be able to get someone to model the two systems and
the results might help you make up your mind.
Good luck with what ever method you end up with...73 de Bill K4JYS (NC)
----- Original Message -----
From: "Robert L Chortek" <Robert.Chortek@berliner.com>
To: topband@contesting.com
Sent: Monday, January 6, 2014 2:51:50 PM
Subject: Topband: Radial Question
Hello Fellow Topbanders -
We are about to embark on a front yard landscaping project at our home on a
tiny 12, 500 sq. ft. lot.
It occurred to me this would be an excellent opportunity to put down a large
number of buried ground radials BUT, they would only cover about 90 degrees
of the compass. Then it also occurred to me I could put down a large number
of radials in our crawl space under the house.
So, my question is, what is the likely negative impact, if any, from the
house being between the 160 meter vertical and the radials placed under the
house? I assume the house material, most of which is wood, tile, sheetrock,
etc. (with the usual house wiring) would be invisible to RF and have minimal
impact.
If I could put down say 60 radials ranging in length from 40 to 120 feet
long, would it outperform my current system with 8 resonant elevated radials
10 -15 feet high (which cover only about 120 degrees of the compass)? I'm
incline to proceed IF it would provide a meaningful improvement in my
transmitted signal strength.
Thanks for any help!
73,
Bob/AA6VB
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