ALL SNIPPED
>
>There are three known but unpredictable losses at work.
>
>One is earth loss because of the poor radial system. Measurements
>show that loss is typically six dB or so with a full size radiator
>(and MORE in a close spaced phased array or with a short radiator)
>when using a small close to ground elevated system, when compared to
>a conventional system. Adding more radials helps this problem by
>reducing current flowing through the lossy soil.
>
>The second is coupling from the radials to anything and everything
>else around the radials. This is caused by the high induction
>(electric and magnetic) fields around the radials. Contrary to rumor
>this source of loss only greatly diminishes in the far field, and is
>helped very little (if at all) by "balancing the current" in the
>radials. Adding more and longer radials DOES help this problem,
>however by reducing the field intensity around each radial.
>
>The third source of loss is the end of the radiator is stuck down in
>the mud, and excited by the feedpoint just as the rest of the tower
>is.
>
>To see interesting and more accurate modeling results, model the
>antenna "correctly" by inserting a resistive load between the bottom
>of the tower and mininec based ground. This resistance partially
>corrects for mininec's incorrect assumption that anything connected
>to the ground is a perfect zero ohm lossless connection.
SNIP
Tom...Rauch that is...I'm getting confused...again.
Are you saying that a vertical with X number of elevated radials is 6dB
below the same radiator with X number of on ground radials?
Or lets try it this way....a ground mounted radial system of say 64
radials would need how many elevated radials at 20' elevation to have the
same efficiency?
If I understand you correctly the work of Chrisman...with top university
credentials...is not to be believed??
My own experience is that the initial full size radiator here with 4
elevated radials 20' high measured right at 37 or so Ohms on a known
accuracy noise bridge...I cant measure in 1 Ohm steps but it was midway
between 35 and 40 Ohms. Based upon K1ZM suggestions I added more radials
and stopped at 12....I could not see a measurable difference on the
bridge.....nor in apparent performance.
I went to the elevated radials at this QTH since I did not want to go
thru the hassle of 25,000 feet of radials that I had at the old QTH. The
system here works very well and the system is now 2 verticals. With only
1200W...QRP as someone mentioned....I rarely have a long wait or miss a
new one.
I would appreciate a bit of clarification. BTW, I am using the standard
feed method...not the N4KG version.
Tnx Carl KM1H
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