[FoxHunt] PicoPlot DF

[Bernie Hunt]

You need to get some kind of directional antenna and a different
frequency. If you have a wide band receiver. Check the harmonics going
upward. 

1	 27 
2	 54 
3	 81 
4	 108 
5	 135 
6	 162 
7	 189 
8	 216 
9	 243 

Till you find one with enough signal to hunt. If you are within 500'
with 130dB then you are probably getting bleed through your radio case.
Getting off frequency to a harmonic may help in a couple of ways. One,
the radio won't bleed signal and two, the antenna sizes are more
manageable. 

Once you know what frequency your goning to hunt one, the you'll need a
directional antenna. Probably the cheapest way is to make a tape measure
antenna cut to your hunt frequency. Since you are hunting a specific
signal, you can tailor your antenna to just that need. Google tape
measure antenna and you should find some good information. 

Since your are in so much signal, you design doesn't have to be that
good, just have a high front to back ratio.

Bernie

-----Original Message-----
From: foxhunt-bounces at mailman.qth.net
[mailto:foxhunt-bounces at mailman.qth.net] On Behalf Of KD7JYK
Sent: Tuesday, July 17, 2007 11:52 PM
To: Ray Brown; Radio Direction Finding
Subject: Re: [FoxHunt] PicoPlot DF

I can get within a 400'-500' circle, but can't see the source.  I can
hear it from 15 miles away, that's what got my attention, so it must be
a fairly large antenna at the source, I am guessing a 1/4 wave and most
likely mounted outside.  I am using a 24" whip and up to 131dB
attenuation and can get very close by spiraling in on the signal, but
can only get so close, within a few pieces of property and at times I
can hear the signal on one side of a street or only in front of one
building, and cannot see any antennas at any of the three sites.  I have
talked to many people that own property and buildings from where the
signal appears to originate, without luck.  I almost need some sort of
sniffer, something small and hand-held like a Geiger-counter, but that
would also require being able to sniff around the land and buildings,
something I don't think people would go for.

Kurt

----- Original Message -----
From: "Ray Brown" <kb0stn at sbcglobal.net>

>   If you're only within 15 miles, then you're going to need something
else.
> You might try one of the Doppler setups that was originally designed 
> for
2m use,
> but at 11m they should be picking up a trace of the signal, hopefully
still
> enough for the Doppler to work...

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