REFLECTOR: Transponder Antenna

[Jim Agnew]

Attached is a picture of the Xponder antenna in the strake end with an aluminum 
ground plate and it works well. Since it is located about 15 feet from the 
transponder I used RG 142 MilSpec cable that is the same size as normal antenna 
wire but equal to the much larger RG8 cable in signal loss. Over 7 feet with the 
regular antenna cable and the high frequency Xponder signal you suffer a signal 
loss of about 1/2 at 17 feet.  Placing the antenna next to the battery may cause 
a dead signal in direction of the battery at low altitudes.  I had this problem 
with the Carbon layups in the wing end of the wing end near the antenna usually 
when talking to a tower and turning or banking slightly would eliminate the 
problem. 


Jim 

James F. Agnew
Jim_Agnew_2 at Yahoo.Com
Tampa, FL
Velocity 173 Elite Aircraft Completed & Flying




________________________________
From: Andrew Judge <ajudge at grovenetworks.com>
To: "VelocityXL at fastmail.fm" <VelocityXL at fastmail.fm>; "reflector at tvbf.org" 
<reflector at tvbf.org>
Sent: Tue, December 28, 2010 12:46:38 PM
Subject: Re: REFLECTOR: Transponder Antenna


Mine is back between the main gear. No probs in 12 years.


________________________________
From: reflector-bounces at tvbf.org <reflector-bounces at tvbf.org> 
To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org> 
Sent: Tue Dec 28 12:06:05 2010
Subject: REFLECTOR: Transponder Antenna 


I am going to put my transponder antenna right next to the battery in the 
nose of the plane. I have a builder  of a  long easy that did this and it works 
great. My concern was  a conversation sometime back about how close to 
the antenna we should be because of the microwaves it emits.
 
Any thoughts on this antenna location?
 
Ron
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