Minitor V Alert output

[FireDawgEMT22]

I would like to take an old minitor V that doesnt work right (alerts but doesnt open up and it is a hardware issue because the programming is right) and hook it up to a station alerting system I would like to build. I want to take the output signal to trip a relay to sound a bell and trip a second relay that will latch itself and turn on some lights. That part of it is going to be easy with some 24V DPST relays rated at a high enough amperage for the lights. I know I can buy a minitor V amplified charger that has this output in it, but I want to do it for as cheap as possible. So just modifying a standard charging base by adding a pin for it would be best.

According to this website https://sites.google.com/site/radioetcetera/home/firestationalerting . The pin that is used for TX to programmer will output a ~2.5VDC signal (relative to pager gnd) when the pager is alerting. The problem is I have checked the voltage on this pin while a pager is activating and got no voltage. Does anyone have any further information about this?

 

[ramal121]

Questions:

1 When you tried to measure the alert output, was the negative lead of your meter on a true ground?
2 Whatever crapped out in the pager might affect the logic output of the pin. Schematics of the minitor V are secret squirrel stuff (maybe wiki leaks will help out someday).
3 Without a charger base, how will you run the pager? Just off the batteries?

If you could get the pager to output 2.5 volts on alert, this might work to trip more relays:
ELK-924 Sensitive Relay
I don't think that output pin has enough nut to run a relay directly. Boosting the voltage to the pager would definitely help. Maybe a wall wart that puts out 4 to 5 volts and wire it in where the battery goes? Gotta get that logic out off of the pin though. Good luck.

 

[FireDawgEMT22]

1 it was the pager ground
2 it was with different pagers other than the one that isnt working right
3 still going to use a charger base, modified with a pin added for the alert signal, just do not want to buy the amplified charger when I can do it somehow with a modified regular charger

And I wasnt planning on using the 2.5 to directly trip a relay, I was going to use it as the gate voltage on an NPN transistor with 24v on the collector and the relay tied to the emitter, then the 2.5 volts should open the transistor to allow the 24v to trip the relay.

 

[FireDawgEMT22]

Got it figured out. It does send a signal of about 2.5V out on the Data TX to Programmer pin relative to the Pager Ground pin (looking at bottom of pager with clip on bottom the pin on top row furthest to the right is voltage and second pin from the left same row is gnd)

It only send the signal will the pager is alerting and was probably too fast for the analog voltmeter I was using the first time I tested it.

I only am estimating the voltage level based on what I have read. I had the voltmeter on 2000mV and it over ranged.