Subject: Re: Pet Locator Design Help Needed
Date: Sat, 11 Jan 2003 07:14:05 -0800
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Direction finding is really the pits. You really
sort of directional antenna. If you're gonna walk
neighborhood with a yagi, you should also wear an
foil hat. ;-)
They make some pretty small pagers these days.
Just phone the cat.
Set it up to administer an electric shock and
"volume" won't be
I'd skip the receiver. Transmitters are much
easier to do.
Crank the duty cycle down and the average power
can be less than the receiver. Use an 8-pin SOIC
PIC that sleeps
most of the time..much like the cat. When it wakes
up,...the PIC... shove the
xtal frequency into a multiplier/filter for as
short a time as
users can tolerate. Tunnel diode impulse generator
should work if you can get a tunnel diode.
Whole thing could be sewn inside the leather
If the cat sleeps in the same place, put an
to keep the battery charged and inhibit the
Put the size and power consumption
in the tracking receiver. Use a cheap police
scanner and a yagi
or sheilded loop antenna. Give one to a neighbor
can triangulate the cat position without ever
I don't know much about feline psychology, but
do mostly the same stuff all the time? You may
once you discover their hideout(s), the radio may
Or maybe get a fish instead. They don't wander so
Barry Lennox wrote:
> On Sat, 11 Jan 2003 01:55:38 GMT, WildOne wrote:
> >I am looking at building a device to help a pet owner find their pet,
> >specifically a cat, in a local neighborhood. The cat would have a
> >collar with a device on it, somewhat described below, and the owner a
> >hand held radio for homing in on the pet.
> There's a very good book on this topic "A Manual for Wildlife Radio
> Tagging" by Robert Kenward, it's a bit rare, but a good bookshop or
> Amazon should be able to get it. It covers everything, including
> transmitters, receivers, antennas, tag mounting, tracking, data
> analysis and animal behaviour. There's also a number of tag designs in
> there, but it is a bit light on schematic details. The smallest seems
> to be about 1 gram with a battery life of 4-6 weeks.
> For more detailed info on schematics, etc, the was a couple of papers
> published in the UK, that have a lot of excellent design details.
> There was also a very good article in Scientific American in about
> 1968 or 69. I have a copies of all these somewhere. The SA one
> obviously uses much older techniques, (definately pre-SMD) but these
> may still be perfectly good for your application. I have copies of
> all these, but it will be a struggle to find them right now.
> The good news is that a cat will be easier than most, as they are a
> large animal, are co-operative (well. most of the time!) and are
> generally tolerant of wearing collars. The suggested max weight of a
> body tag is about 2-4% of the animal's weight, so you could build a
> pretty hefty one for a cat.
> Barry Lennox
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