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Old June 25th 07, 03:01 AM posted to rec.radio.amateur.antenna
[email protected] nm5k@wt.net is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 757
Default Guy from university physics ... Eureka! A picture!

On Jun 23, 8:44 am, John Smith I wrote:
wrote:

...


Well, it appears to me, the shortened 10 meter 1/2 is superior to a 1/4
(both mounted mobile) and the shortened 1/2 is VERY close in performance
to a full ~17 ft. (vs. ~5.3 ft. shortened--with the top hat and spacings
optimized, the difference is less than the width of a meter needle.)


I assume you mean winding a 1/2 wave winding on a short stick.
I could see that maybe beating a 1/4 wave if the ground system was
not the greatest..
But I don't really see it happening over a good ground, where
the 1/4 wave isn't really stunted.
It's quite possible for for a 1/4 wave whip on a bumper, to
lose to a loaded whip half it's size, if mounted on the roof.
So on a car/truck, the location can make a big difference..
CB'ers have run those things for years under various names.
I can see cases with lousy grounds where a 1/2 wave, even
short might be worth a try. But I once did a comparion with my
standard "1/4 wave tuned" mobile on 15m, vs using my 40 meter
setup on 15m as a "extended winding" psuedo 5/8 wound whip.
The normal 1/4 wave setup was the best.


This silly combination of know "tricks" is certainly doing something
which common place formulas/equations don't account for ...


Ground, or lack of it could account for it. Same mount location, etc?
Bumper, trunk, or roof?
A mobile is not the best place to test vertical antennas.
Too quirky...The car is half the antenna.
Sure, you can see which one works best, but it's not a
very good test platform in general. I'd rather test over a
specified quantity of radials, if ground mounted.
Ditto for elevated, the only difference being the number
required drops as you increase height.

However, if you already naysay on the navy data, I won't be able to
present any proof which even comes close--my equipment budget doesn't
even begin to match that of the navys' to begin with ...


I don't know what navy data you are talkng about.

Too bad a bunch of different people don't use a standard test jig, apply
their own modifications and generate a ton of data/results ...


I don't know what you mean by "test jig".. What you have as far as
a "test" antenna, or having a location with a specified ground
quality?
MK