GPO 312F conversion help

[Dappydan]

Hello people.
I have got myself a GPO 312 telephone.
I thought I would try too get it going so I followed the convertion instructions on http://www.britishtelephones.com/pstconv1.htm#312 but I still have an issue.
If I receive a call the telephone will ring. I lift the receiver and the bells stops. The phone making the call still has the ringing tone and when I put the handset down it comtinues ringing. 😁
Any ideas would be great.


Thanks in advance.

[Dave Moll]

That implies you're not making a loop when you lift the handset - i.e. the line does not detect you going "off-hook". The most likely source of trouble is high impedance or open circuit across the transmitter (microphone) circuit. If you have a multimeter, set it to ohms, and while the telephone is not connected to the line check the reading between the red and white leads of the handset. Another possibility is dirty contacts in the handset cradle switch - though clearly the contacts to the ringer are working correctly.

[Dappydan]

Hello Dave,

I feel like an idiot now because, I have had the phone stripped out for cleaning and I thought I would convert the wiring whilst its all stripped out, before puting it all back together i thought it best too try it, well i hadnt connected the handset as i thought it wasnt nessasery to at least ring and answer. I will put it all back together and try again.

Thank you for the advice.

[Dave Moll]

Yes - a disconnected handset would certainly cause the stated problem!