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[aprssig] Helmet Antenna - dont bother.

Robert Bruninga bruninga at usna.edu
Mon Mar 7 00:25:14 UTC 2005


Today I was tail-bike on a marathon.  
Lesson:  Dont bother with a helmet antenna
for voice.  (APRS maybe, but not for just voice).

I took one of those tiny 19" mag mount
whips with a small base (like a kisses chocolate piece)
stuck it inside the helmet protruding up through the 
air holes, covered the inside with aluminum foil and
then let a can lid stick to the bottom of the magnet.

I also, carried an identical HT with its own
long whip.  Conclusion was generally no difference
after lots of side-by-side tests...
Therefore, dont bother.

An HT held to my mouth with a similar 19" whip is 
going to work similarly as a 19" whip on the helmet at 
the same height.  I had just hoped that the slightly
better ground  plane might work better than the HT with 
no real  counterpoise.... dont bother.

Now, for APRS where you are not holding the HT to
your mouth, then maybe the extra height and lack
of body blockage is worth it.

Just 2 cents...
Bob






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