[Fwd: RE: [Mobile-Portable] New car and considering new antenna setup!]

Sat, 08 Mar 2003 18:18:06 -0500

-------- Original Message --------
Subject: RE: [Mobile-Portable] New car and considering new antenna setup!
Date: Sat, 8 Mar 2003 12:50:49 -0600
From: "Jack Mitchell" <[email protected]>
Reply-To: <[email protected]>
Organization: Saturn of San Antonio
To: "'Art Clemons'" <[email protected]>

Hello all,

There have been several "shoot outs" in California. They have mostly
compared HF mobile antennas on 75 meters. The reports I have seen from
there indicate that, on low bands, the "bug catcher" is number one. In a
close second is the large coil center loaded screwdriver type antenna.
Everything else has a significant decline in radiated signal strength.
On higher frequencies the difference is less noticeable.

So, the question is, what band do you work most often and what signal do
you demand? Make all decisions from that perspective.

Art, if this foes just to you, please submit it to the list. Thanks and
73.
Regards,

Jack Mitchell
Team Leader
Saturn of San Antonio
5720 N.W. Loop 410
San Antonio,Tx 78238
210-681-2828
800-728-8766

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Art Clemons
Sent: Saturday, March 08, 2003 12:02 PM
To: [email protected]
Subject: Re: [Mobile-Portable] New car and considering new antenna
setup!

 > As mentioned, some of the screw drivers are base loaded and some are
low
 > center loaded, none are top loaded.  The Comets and the Diamonds are
top
 > loaded which is the tremendous advantage.  A top loaded configuration
works
 > the best.

I don't know why you would think that a thin top loaded antenna would
work better in a mobile environment, and in fact, the thin design to
allow top loading if that's what the Comet's do, leads to less
efficiency than centerloading.

Now a 6 inch diameter Bugcatcher which is mounted at the center will
out-perform a screwdriver, but then again a top hat on a bugcatcher will

usually out-perform just a bugcatcher.

 >>Further, there have been
 >>numerous shootouts on 75 meters and 40 meters with the same output
power
 >>comparing antennas like the Screwdriver and the Comet, the Comets lose

 >>every time.
 >
 >
 > I haven't seen any reports of such shoot outs.  Though I suspect that
an
 > honest comparison would show that the low cost Comet and Diamond
antennas
 > to be a lot better than many would have otherwise thought!

You haven't been on this list long enough, they've been posted several
times.  You might also want to look at the September 1995 issue of
WorldRadio for one sample.  You can also search google's back list for
internet postings.  In fact, on this list, the results have been done
several different times.

 >>Anyone who has ever tried both on the same mobile will
 >>notice the difference quite readily.
 >
 >
 > How one mounts the antenna has a lot to do with it.  Most screw driver
 > installations are installed on the lower portion of the automobile,
such as
 > a tow bracket, or bumper, which is certainly not an optimum location.
A
 > Comet or Diamond mounted at that position would certainly not work
well,
 > but if the Comet/Diamond is installed up higher which is usually
possible
 > with its low profile, then the results are quite spectacular.
 >

Actually, the only thing that might let a Comet/Diamond out-perform a
screwdriver is mounting the bottom of the coil on a screwdriver below
the roof of the mobile, and even then, I would be really shocked.  Just
try the two on the same mobile for yourself.  When I add in the
fragility and the like, it's an even worse choice.  Quite frankly, for
about $170, one can buy a working W6AAQ screwdriver, and one can build
one for even less, using plans that are readily available.  I can't see
spending over $50 to build one if one can get some 2 in diameter
Aluminum tubing of the proper length.

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