[aprssig] Killer APRS use! ;)

[Curt, WE7U]

On Thu, 9 Mar 2006, Dave Baxter wrote:

> The "Transponder" class of device is probably the better bet, than an
> APRS beacon.
>
> I used to have some designs for a single transistor VHF "Pinger" you
> could detect with a normal broadcast RX.  It just "pinged" once a second
> or so, very short pulse duration, more a ringing LC circuit kicked by a
> unijunction I think.
>
> Worked off a single dry cell, but no idea where the designs are now :(

I had the opportunity to play with a cougar collar at college for a
bit.  It was pretty much the same thing:  One short duration pulse
on VHF every XX seconds.  I think it lasted a year or more on one
battery.  If I recall correctly it was turned on by a magnet so must
have had a reed switch inside.  I didn't get to take it apart.
These were fairly frequency stable so you could tell the various
animals apart by their frequency.

--
Curt, WE7U.   APRS Client Comparisons: http://www.eskimo.com/~archer
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