Observational note on radials on the ground. My 43x130 foot
inverted-L requires more inductance in the summer for resonance. I
see the change about a month after ground freeze-up (but that may
vary with moisture content of the ground). Fall usually exhibits
saturated ground due to the rainy
asking anyone to put up something we haven't already tried
> and tested.
>
> 73, Guy.
>
> On Tue, Dec 21, 2010 at 10:32 AM, Steve Ellington
> wrote:
>> Logically .
>>
>> You may as well have a big loss in the near-field and get it over with.
>>
>&g
e -
> From: "Guy Olinger K2AV"
> To: "Tony Estep"
> Cc:
> Sent: Tuesday, December 21, 2010 10:28 AM
> Subject: Re: [Elecraft] Inverted-L (was OT: Vertical antenna)
>
>
>> The only thing I would point out about the article is that it
>> basically
Actually, a DENSE radial solution in the near field DOES return
dividends, even over poor ground. The savings has to do with field
cancellation at the ground, caused by uniform radials and the vertical
radiator presenting equal and opposite fields to the dirt. This
cancellation zone then "returns
2010 10:28 AM
Subject: Re: [Elecraft] Inverted-L (was OT: Vertical antenna)
> The only thing I would point out about the article is that it
> basically is a tabulation of model results, an extension of the model
> presentation, what do you get if you run the model over and over kind
> of thing.
The only thing I would point out about the article is that it
basically is a tabulation of model results, an extension of the model
presentation, what do you get if you run the model over and over kind
of thing. The modeling of dirt is in itself an attempt to extend a
limited paradigm of MF measur
Guy,
OK, I missed by a factor of 10.
I am using 2 elevated radials per band, and the physical direction is
such the pairs are horizontally opposed - that should reduce the
radiation from the radials to zero (or nearly so).
I first cut the radials 15% longer than the "formula" would indicate,
Guy,
OK, I missed by a factor of 10.
I am using 2 elevated radials per band, and the physical direction is
such the pairs are horizontally opposed - that should reduce the
radiation from the radials to zero (or nearly so).
I first cut the radials 15% longer than the "formula" would indicate,
It's that ugly green stringy stuff some people use to hide their
beautiful brown dirt so that nobody tries to steal it.
Dave, AB7E
QTH not far from N7WS
On 12/20/2010 10:37 PM, Wes Stewart wrote:
> I just have one question: What is grass?
>
> --- On Mon, 12/20/10, Guy Olinger K2AV wrote:
>
I suspect that Don was referring to the fact that poor ground
conductivity affected his low angle performance, and that is absolutely
true. There isn't a thing he or anyone else can do to change the far
field effects of poor ground. He can add lots of radials, buried or
otherwise, to improv
I just have one question: What is grass?
--- On Mon, 12/20/10, Guy Olinger K2AV wrote:
>
> Many people are adopting a construction technique as
> primary over
> performance considerations, e.g. lay out wire and hold them
> down with
> lawn staples and let the grass grow up around them, holding
I hope people doesn´t learn from this statement.
IMO this is as far from logic one can get.
/Jim
--
On 2010-12-21 02:27, Don Wilhelm wrote:
>
> The ground conductivity in my area is not the greatest, so I have
> accepted the logical consequences of that fact.
>
> 73,
> Don W3FPR
>
_
15 ohms miscellaneous in series with 32 ohm radiation resistance, only
3%? Don't you mean 30%?
What were the lengths of the elevated radials and how many?
73, Guy.
On Mon, Dec 20, 2010 at 8:27 PM, Don Wilhelm wrote:
> Dave,
>
> If you read the radial tuning procedure in Low-Band DXing, you wi
For those who wish to pursue the radials question further, here's one of the
many publications on the subject. This one is replete with numerous tables
and graphical representations of the incremental value of more and longer
radials in various types of soil:
http://www.ncjweb.com/k3lcmaxgainradia
Buried BARE radials of sufficient number will show far less "tuned"
behavior and self-terminate more rapidly.
BURIED bare wire radials and ON THE GROUND bare radials measure quite
differently. This too is something you can verify by experimenting
with a bare wire DOG on top of the ground vs an en
Dave,
If you read the radial tuning procedure in Low-Band DXing, you will find
that it "all comes out in the wash". Yes, your statements are correct,
and in fact that is how I did mine. Although I did not resonate my
vertical monopole against any ground plane - I simply cut the lengths to
> maintained with non resonant radials or resonant radials are used, eff and
>> match
>> will remain . Example, a mag mount antenna or a ground plane vertical with
>> three or four resonant radials works fine and any elevation. Just a point of
>> thought.
>>
>&
three or four resonant radials works fine and any elevation. Just a point of
> thought.
>
> Mel, K6KBE
>
>
>
>
>
>
>
> From: Steve Ellington
> To: Guy Olinger K2AV; Vic K2VCO
> Cc: elecraft@mailman.qth.net
> Sent: Mon, Decembe
That's my experience too. Your Inverted L has a much, much higher impedance
than any Marconi antenna on any band where it's 1/2 wave or longer. That
makes the efficiency far less dependent upon the ground and the effect of
the ground much less.
Ron AC7AC
-Original Message-
Now here's th
That's my experience too. Your Inverted L has a much, much higher impedance
than any Marconi antenna on any band where it's 1/2 wave or longer. That
makes the efficiency far less dependent upon the ground and the effect of
the ground much less.
Ron AC7AC
-Original Message-
Now here's th
On Dec 20, 2010, at 12/203:44 PM, Steve Ellington wrote:
> Some of your comments were verified in a recent QST article.
>
> Mar 2010 - QST (Pg. 30)
A more complete version of Rudy's study are in 6 parts in the 2009
issues of QEX.
"Experimental Determination of Ground System Performance fo
Subject: Re: [Elecraft] Inverted-L (was OT: Vertical antenna)
Guy:
Very interesting
Some of your comments were verified in a recent QST article.
Mar 2010 - QST (Pg. 30)
An Experimental Look at Ground Systems for HF Verticals
The author experimented with resonant vs nonresonant radials on the
On 12/20/2010 1:48 PM, Don Wilhelm wrote:
> There are good reports of elevated radials, although some measurements
> by Tom Rauch W8JI indicated some disagreement, but for my situation it
> is the best solution despite any controversy.
Elevated radials are great until the metal thieves get arou
Guy:
Very interesting
Some of your comments were verified in a recent QST article.
Mar 2010 - QST (Pg. 30)
An Experimental Look at Ground Systems for HF Verticals
The author experimented with resonant vs nonresonant radials on the ground
and found performance improved when the radials were
Don's comments reminded me of an article I read a while back about elevated
radials used by commercial AM broadcast stations that may be of interest:
http://www.scribd.com/doc/34884702/New-AM-Broadcast-Antenna-Designs-Having-F
ield-Validated-Performance-by-Clarence-M-Beverage
Yes, the author's na
Guy,
I know it is not equal to your statements, but in my mind you are making
a good case for the use of elevated (and tuned) radials. L B Cebik
recommended them to me at FDIM several years ago over in-ground radials
and I have never done the work of burying the radials, so I have no
compar
raft@mailman.qth.net
Subject: Re: [Elecraft] Inverted-L (was OT: Vertical antenna)
Dick, my research would say probably not. The exception would be if your
lot is
such that you could run more than one shorter wire and can't run a single
one.
Also you might be able to make a capacity hat wi
Elliptical? I suppose so. But simply stating the facts seems to have
little effect and just gets bashed, where wading through the issues,
however elliptical, seems to give the nay-sayers some pause, and have
some effect. Radials, even in 2010, 80 years after the last
definitive research, are sti
If the horizontal wires run parallel to each other, it will start to look
like the old LF antennas Hams used before we moved into the "short waves".
They typically had a number of horizontal wires running parallel held apart
by spacers and erected as high as possible.
Those were really top-loaded
arily for installation convenience
which varies from QTH to QTH.
Willis 'Cookie' Cooke
K5EWJ
From: "Edward Dickinson, III"
To: elecraft@mailman.qth.net
Sent: Mon, December 20, 2010 12:16:53 PM
Subject: Re: [Elecraft] Inverted-L (was
On the Inverted-L off topic, is there anything to be gained, or lost for
that matter, by having more than one of the horizontal portion of the
antenna?
73,
Dick - KA5KKT
__
Elecraft mailing list
Home: http://mailman.qth.net/mailman/list
Another antenna for top band that's worth considering is a Double L (Don
Toman, K2KQ) www.yccc.org/Articles/double_l.htm . It is essentially a
vertical dipole with the ends bent parallel to the ground and in the same
vertical plane. So, if you have, say, a 70 foot or higher tower, you can
raise th
That's why I prefer an end-fed dipole to a Marconi antenna, even if I have
to get creative to get wire up and in the clear.
The advantage is that the high impedance feed point at the end means very
little current flows, so very little current need flow into the "ground"
connection. Very little cu
Your post is a little elliptical, but am I to understand that you are saying
that there
are resonant effects noted with in-ground radials when the wire is insulated,
but not when
it's bare?
If that's true it's interesting and I hadn't heard it before. Most writers on
the subject
simply say t
(For the record, I am also addressing some off-reflector extensions of
this thread with a single post.)
We are still talking about an end-fed antenna for 80-10 which presents
unique problems. Trimming the horizontal length of up 30, out 30 for
a good match will help a lot. But that will not addr
Going from loop to vertical involves two very different lob patterns. It
was never mentioned if the antenna performance was to favor local or DX. Here
is one which it does not matter as it adapts for both.
A nice compromise antenna which takes into account:
---high and low angle lobe patterns
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