Seismic detectors informational thread TRC3A

[1Admin]

Not for anyone in particular but for folks new to these sets-

On the TRC3A's, the FREQUENCY with which that probe/transmitter transmits on is LISTED ON THE PROBE ITSELF, right where it says FREQUENCY on the data plate. That is the RADIO FREQUENCY that you will hear the tone code for that probe on. You will NOT hear it on an "am/fm car radio", it will not be broadcasted on station 99.1 WROL on your CAR radio....

A cheap- didn't say GREAT, said CHEAP- radio that is in the frequency range is here-

http://www.radioddity.com/us/baofeng-uv-5r-sp-mic-136-174-400-480mhz-dtmf-ctcss-dual-dand-fm-ham-radio.html

Yes, a whooping $34. I wouldn't expect a lot.

MOST survivalists already have radio sets that will usually hear the frequency range of the TRC3A- a decent 2 meter radio. However if you don't, above is a $34. option.

[prc-104]

PSR1 and 1A's

Thought I'd mention this on the wired detectors.

Yes, they have connections for 4 sensors....... but ..... a fellow .... a clever fellow .....can attach up to 4 sensors to each connection and use a set of switches so he could isolate which one of the four was sounding off.
So you can actually use 16 sensors per PSR1 or PSR1A.

Another thing.
And I use a little creamcolored radio shack amplified speaker for this that runs on a 9 volt battery and comes with clip leads for the audio input.

What you do with the audio amplifier is turn it on and connect it to one of the sensors. Now you can listen to the sensor. That's why they're called geophones.
Pretty cool really.
You can hear peoples conversations, truck engines running, footsteps, twigs breaking, all in all pretty cool.

BTW, this obviously doesn't work with the wireless ones.

So 1Admin is definitely calling it right.
These things are fracking amazing how well they work.

[justanothergunnut]

I have a couple questions
1.On the wireless detectors what is the max range from the probe that it can reliably pick up normal human foot traffic?
2. I understand the wireless units are operating in the 2m range correct.. What frequencies? range not exact.
3. IF someone was working on a updated version would it be more advantageous to be in the MURS frequencies?

[tech]

Frequency range is on the lower end of the VHF air band...around 130 mhz +/- 5mhz.