I had a trip to the coast last week to pick up a couple of GPO 'pyramid' phones I'd won on e-bay. When I areived, not only did I get what I had gone to collect, but I was also offered two other items. One was a CB935 switchboard (that's a story for another thread) and the other was a battery phone, which were once used on the rail network here in the UK. So i picked up the lot for £50 and set off for home.
The railway battery phones are normally made by Ericsson. However this one has a handset with a Siemens mark cast into it. The paste label inside is Ericsson though, so i guess the handset must have been changed at soem point.
There are a few problems with the phone. The caps of the press buttons on the front are missing, the capacitor is present but not fitted and the hook-switch didn't seem to be making and breaking all teh contacts the way it should.
The first thing I've looked at is the hook-switch. I removed it from the phone to make inspection easier and found it's metal base to be wildly bent out of shape. So I dis-assembled it from the stack of contacts (I managed to keep the contact stack all in order and quickly put a screw back through them) and went to find something to use as an anvil to hammer the plate straight again.
The plate is now reasonably straight again and the hookswitch has been reassembled. I've visually checked and adjusted the contacts to make sure everything is making and breaking as it should. Next stage will be to do some continuity tests with a multi-meter to make sure the contacts are clean. But for now it's back in the phone and I'm ready to move on to re-fitting the capacitor.
Does the handset have a push to talk bar in the middle? There's 3 old test boards in a local CO that has these handsets with the cups (spit cups?) and push buttons. Wonder if they're rare?
Quote from: CanadianGuy on June 06, 2019, 03:44:30 PM
Does the handset have a push to talk bar in the middle? There's 3 old test boards in a local CO that has these handsets with the cups (spit cups?) and push buttons. Wonder if they're rare?
I'm not sure if the push to talk handsets are rare, but less would have been made than the standard 164 handsets. This style of handset were for use in noisy locations. The person on the other end of the line would be able to talk without having to listen to the background noise of the person they were talking to, who then pushed in the centre bar to respond and be heard.
There's no push-button on the handset. It looks like a standard GPO type handset manufactured by Siemens in their millions, so probably not rare at all. I'm also not sure it's the original handset as it's an Ericsson phone with a Siemens handset, so I guess that bit got swapped out.
As always, I'm interested in the schematic, so could you please try to take a picture and post it?
Quote from: dsk on June 07, 2019, 09:37:33 AM
As always, I'm interested in the schematic, so could you please try to take a picture and post it?
I'll see what i can do. I'm not quite sure how to get a good shot of it because of where they've stuck it though.