So in the stuff called life, I lost
my wallet. I lose things all the time.
So I tried to make a tracking transmitter
with things that I have sitting around here
because there is zero dollars.
I have a weather station transmitter that sends
out a digital pulse once a minute on 434.92 Mhz.
It has some things going for it. It runs for more
than a year without running down the 2 AAA batteries
that are in it. I can hear the pulse on in ICOM IC-R2
pocket sized scanner/receiver. But the pulse is very brief.
I can live with that. But the signal is digital and is spread
out over a MHz or so. Really really hard to track. Still fun
to experiment with. At least the batteries don't run down
for a long time.
So I looked around the junk pile that I still have here -
and found a 49 MHz walkie talkie. I put a rechargable
"9 volt" battery on it, took the mic/speaker off, and shorted
the transmit switch and shorted the switch that makes an
audio tone. This was really good. With a 2 inch antenna
on it - it went about 10 or 20 feet. Perfect in a house.
You just walk around until you hear it, and when the signal
strength indicator gets up to pin, you have it. It's about
the size of a pack of cigarettes, but that doesn't matter.
BUT, the thing only runs for about 10 hours.
So - what I was thinking - was - find the minimum voltage
the thing runs on - and it won't be drawing much current -
hopefully. Then try that and see how long it goes.
If that works, make a battery pack with MORE voltage,
and put it on a circuit like a regulator or something and
it will run longer (will it?) as the battery voltage slowly
drops down from the max value to the minumum operating
voltage value. Maybe it will go a week or so, which I
can live with. Maybe it will go longer. Who knows?
So if you guys have any ideas about this or any other
ideas let me know.
This is for a purpose, but it's for fun, too.
By the way - I found my wallet - but only
after I had replaced most of the stuff in it.
Bruce