[FoxHunt] antennas for harmonic sniffing

[Kuon & Dale Hunt]

>Great idea..
>
>The 5th (6th) harmonic getting out is a very transmitter specific issue.
>A good pi network in an ammo can transmitter has 3rd harmonic at the
>connector down about 45 dB and the 5th is down another 15 or so...

   Granted it will vary a lot.  The ELT has a high harmonic
   output (mine has two class C amps following the AM modulated
   stage!)  Actually I added an extra output filter to help
   remove the 243 MHz component on the practice beacon.

   And, of course, any hider who expects hunters to use harmonic
   sniffing will pay particular attention to output filtering.

   My point with the distances was to establish a reasonable
   maximum beyond which one should not to expect it to work.
   You still have to deal with reflections and obstructions.
   Since I have other toys that work up close, I probably would
   only use it inside a building or otherwise where the small
   antenna is an advantage.

   It is just another tool to have on hand when you need it -
   and, if you already have a receiver, an inexpensive one you
   can use for hunting either band.  (In theory an antenna
   that covered 850 - 888 MHz would also work for both ELTs
   and 2m, but the 2m harmonics fall in the cell-blocked
   frequency range on my radio.)




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