MC-131 ringer

[Babybearjs]

  wanted to double check with you guys... can the MC-131 Ringer the goes to the army field phone be used on a regular land-line? I got JUST the ringer and want to use it, but am not sure if its compatible with the line... using a standard 0.5uf cap inline with it... I have a 3 bar magneto and it rings fine through that... if its a 48 volt ringer, what size resistor should I use to get it to work?

[rdelius]

It can be used but has no bias spring to prevent ring tap when dialing

[Babybearjs]

thanks! I'll give it a try!

[dsk]

It will be no problem to use it.
I have measured a little, mine has a DC resistance of 1220 ohms.
In series with a 0.5 uF capacitor it has an impedance of approx 9565 ohms at 25Hz.
That should give a REN load of close to 0.75.

The field telephone EE-8 in CB mode is made for use on a landline (manual exchange)  and has a large REN load of close to
3.25! but here you have the load of the ringer with a 2 uF capacitor + the load of the voice circuit kept in all the time.

If you need an anti tinkle spring, you may take spring from a pen.


dsk

[Babybearjs]

Thanks!