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ACRO E-mail Archive Thread: [Acro] Re: ICOM A200

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ACRO E-mail Archive Thread: [Acro] Re: ICOM A200


Thread: [Acro] Re: ICOM A200

Message: [Acro] Re: ICOM A200

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From: "Tom and Lori Adams" <Flickroll at>

Date: Thu, 21 Jun 2001 15:13:15 UTC


  Radios have always been a problem in Pitts a/c. A friend of mine ,Erik
Mingeldorf, built a beautiful S!-S and mounted one of the ICOM antennas on
the belly panel behind the fire wall on the left side. If I remember right
it was slightly forward of the spring gear............It looked great and he
said it worked great....
Ya might try it.......It might work....

Tom Adams
-----Original Message-----
From: postema <hans.postema at>
To: mike and kelley morrison <toydoc1 at>; acro at
<acro at>
Date: Thursday, June 21, 2001 4:10 AM
Subject: [Acro] Re: ICOM A200

>Just yesterday I measured the antenna on my S1S. I think that it
>is the same as yours, a wire with a sharp bent towards the tail,
>under the belly.
>My friend has what he called "reflectometer" (in French). This
>device measures the power reflected by the antenna compared to
>the power that leaves the transmitter. At the first measurement,
>the antenna was in the middle of the red zone. The red zone
>starting at 3. We bent the antenna down until the point where
>it touches the ground. This helped a lot, measurements are then
>outside the red zone, sometimes around 2.
>Measurements were performed on the ground, either with the tailwheel
>2 feet or 7 feet off the ground. There is no difference in
>performance between 2 and 7 feet, which makes us conclude that
>the ground effect is not too important. (on dry asphalt)
>Our conclusion is that the bent antenna is bent too much for
>proper functioning. Since I land mostly on grass runways,
>an antenna touching the ground is not a final solution.
>For reference we also measured a similar antenna on top of the
>cabin of a high wing airplane. (Rans Coyote)
>This one worked flawless but the bent is probably a bit less
>than 45 degrees compared to much more than 45 degrees (60?)
>on the Pitts S1S.
>I hope that an electronics expert on the list can translate
>this talk into proper electronics-english and that someone
>can give suggestions for a correct antenna. I will use
>the Bendix KX99 which has only 1.5 Watt so there is not
>much power to waste.
>Greetings from Geneva in Switzerland,
>           Hans.
>> mike and kelley morrison wrote:
>> I am having a problem with the com in my s1s it was a terra ( this has
>> been a big POS) I just got a new ICOM A200 and am wondering if the
>> bent whip antenna (mounted on the belly) will work. Any advice would
>> be great.
>>                     Thanks Mike Morrison Pitts N93DB


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