[FoxHunt] antennas for harmonic sniffing

[WolfBob]

I think the key advantage is the ability to have a small antenna with 
very narrow lobe and therefore good accuracy. The 6 el widespaced 
antenna I built at 732 is 1.2 wavelengths long or the same beamwidth as 
a 7 ft 2 meter yagi and it is just over 18 inches. Another toy in the 
toybox..

Bob, WB6JPI

Kuon & Dale Hunt wrote:

>>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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