When I first looked at Eddy's list I laughed.
However, it does convey a clear message that there are a lot of ways to
achieve the goal of a workable low-band vertical.
I certainly won't argue with the quest for an answer to the "what is best"
question, but at some level almost every ham has to settle for the best that
they can reasonably do.
The K2AV FCP idea is really good for people who want to have a decent
antenna on 160 and where concealing all the wires along a backyard fence
line fits their idea of combining aesthetics with performance. It is a
great idea but is probably not as good as a situation with 120 perfectly
spaced ground radials or 60 perfectly spaced elevated radials.
Tom, W8JI, and others can put up really great layouts in open fields but
this is not an option for many hams. Thus, we get to the situation Eddy
reveals ....Do what you can reasonably do and don't worry about every
theoretical Db or fraction of a Db.
Personally, I don't want to walk out into my backyard and have to look at a
bunch of wires drooping all over the place. That is why I like K2AV's
design. Other people think differently.
So be it. Put something up and get on the air. A new country might show up
while you are fiddling with one more radial.
----------------- Wes Attaway (N5WA) -------------------
1138 Waters Edge Circle, Shreveport, LA 71106
318-797-4972 (Office) - 318-393-3289 (Cell)
Computer Consulting and Forensics
-------------- EnCase Certified Examiner ---------------
-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Eddy
Swynar
Sent: Saturday, March 02, 2013 7:48 AM
To: topband@contesting.com
Subject: Re: Topband: Elevated Radials
Good Day Again All,
Well, I've done my best to summarize all the respondents' comments in the
matter of elevated vs. ground-mounted radials---and I'll try now to
summarize these in a single-page format for benefit of all to see...
The results are certainly interesting, and some are as different from one
another as we might be physically!
In any event---and FWIW---here goes:
(A) Is it true that a couple of elevated radials are just as effective as
the "optimum" amount of buried ones...?
-It depends.
-Don't know.
-Don't know.
-If 2 or more are used, maybe.
-It depends.
(B) What is the "ideal" number of elevated radials that one should use...?
-It depends upon their height.
-2.
-2 to 4.
-7 to 8.
-1 to 5.
-2.
-8.
-1 to 2.
-16 to 32.
-16 to 32.
-The more the better.
-Any amount, but use pairs (ex. 2 to 4, 6 to 8, etc.).
(C) How many elevated radials are "just enough"...?
-Enough to overcome ground losses & establish resonance.
-2.
-2
-2.
-2.
-4.
-4 (8 is overkill).
-1.
-32.
-8.
-Depends upon soil quality
(D) How high should these radials be...?
-The higher the better to clear pedestrians, animals, etc.
-10'.
-6' to 8'.-6' to 8'.
-12' to 14'.
-7' to 8'.
-6' to 15'.
-20'.
-6' to 10'.
-8'.
-10' to 12'.
-20'.
-1' to 10' (but the higher the better).
(E) Would it be a requirement that I raise the feedpoints of my "L's" to the
same height as the elevated radials, or can I simply leave the bases where
they are now (at ground level) & simply slant the radials upward with no
effect upon performance...?
-"Gull wing" arrangement OK.
-Feed point should be 8' high.
-Not sure.
-Makes no difference.
-"Gull wing" OK.
-"Gull wing" OK.
-Not sure.
-Same height as radials (to minimize ground loss).
-Makes no difference.
-Optional.
(F) Is it OK to bend the elevated radials to fit property allotments...?
-Slight bends OK.
-Yes.
-Yes.
-Yes.
-Not sure.
-Not sure.
-OK, but gradual bends only.
-No.
-Yes.
-Best kept straight.
(G) What is the desirable length of an elevated radial...?
-Quarter wave.
-Quarter wave.
-Quarter wave.
-Quarter wave.
-Quarter wave.
-Quarter wave.
-Quarter wave.
-Quarter wave.
-Quarter wave.
-Quarter wave.
-Use short radials with a common coil.
-Quarter wave + height above ground.
(H) Should any existing connections to real earth at the base of the "L's"
(i.e. a ground pipe) be completed severed with a system of elevated
radials...?
-If radials one quarter wave long, makes no difference.
-No ground.
-No ground.
-With a ground, there'll be noise on receive.
-NEVER ground.
-No ground.
-No ground.
-No ground.
-No ground.
-No ground.
Additionally, four respondents recommended using a choke balun at the
feedpoint...one person avowed that a single elevated radial was the
equivalent of 30 ground radials...another stated that 8 elevated radials
were "super good", but that even 1 to 2 would be good...another affirms that
one simply can not beat the optimal number of buried radials...
Several recommended this site as an excellent reference as well:
http://www.antennasbyn6lf.com/2012/02/elevated-radial-ground-systems-some-ca
utions.html
I personally haven't taken a look at it myself here, but it is most
certainly on my "to do" list!
I hope my effort here might help dissipate some of the "fog" surrounding
elevated radials, vs. ground-mounted ones---certainly there's stuff here
that I wanna digest still...and again, I thank one & all for their feedback,
& trust that I've done justice here to your many responses...
~73~ de Eddy VE3CUI - VE3XZ
_________________
Topband Reflector
_________________
Topband Reflector
|