[TowerTalk] Elevated GP vs. Vertical Antennas

[Jim Reid]

At 08:15 AM 3/5/98 -0600, T A RUSSELL wrote:

>N4KG  response  below -
>
>> Raised resonant radials radiate like crazy and couple 
>>to EVERYTHING else in the near field (including lossy soil below the 
>>antenna) no matter how much time is wasted pruning and tuning. The 
>>fields from each radial only cancel completely hundreds of feet away, 
>>and that is where they don't cause power loss.     (W8JI)

bit snipped about the tower

>>Raised radials are a great idea if they are installed a hundred feet 
>>in the air, but place anything (including good ole dirt) within a 
>>pretty large distance and the radials couple like crazy to 
>>whatever the other conductor is. And that's true no matter how 
>>much time is wasted "tuning and pruning" them for equal currents.
>>
>>73, Tom W8JI
>>w8ji.tom@MCIONE.com
>>

>Hi  Tom  -
>
>I agree that  my elevated GP antennas have losses due to 
>the earth  connection  and low radials, but you make it sound 
>like such antennas are not much better than a dummy load 
>and on this point I must STRONGLY  DISAGREE.
>
>(My GUESS at  WORST  CASE  losses compared to a full size ground based
>vertical with lots of radials is 6 dB.   My HUNCH is that it is actually
>much LESS.)

How about the performance of the 6Y4A   elevated radial antennas
during last year's contests?  See Feb and March CQ-Contest.  Used
Force 12's verticals,  and Tom  raised the radials,  only two or three
feet,  were "completely" decoupled from the ground;  impedance 
came right into the 30 ohm area as it should for 1/4 wave verticals.
Also set world class scores with them down there.

Or consider W1XT's score in the recent  CQWW  CW test:  792,438 points,
916 Q's and 289 multis:  all using monoband Gladiator verticals,  with
the antennas raised about 10 feet,  from which elevated,  resonant
radials,  four per antenna are run out.  He was on poor ground,  in
Arizona;  even got 23 Q's and 18 multis on 160 using the 38 foot
top loaded Gladiator;  76 and 34 on 80;  296/65 on 40;  271/77 on 20;
192/63 on 15 and 58/32 on 10 meters.  All done in 30 hours of
operating using monoband verticals only. No one else 
on the desert in the SW has apparently reported better scores, 
at least as far as I know.

So they do work pretty well!!

73,  Jim,  KH7M
On the Garden Island of Kauai and putting up a complete 
suite of Gladiators!



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