Help with a 312L telephone

[petertheorgan]

Hi everybody

I have just been given a 312L telephone complete with the "call exchange" button on top which I am led to believe was used when the telephone was used on a party line.

The telephone is in very good condition but sadly the bells are missing (the clapper and coils are present) so my questions are:

1) Is it possible to get the correct bell domes? I was going to ask before I put a wanted in the correct section.

2) Can anybody give me the correct wiring diagram to reconnect it for plug and socket use and tell me the correct terminals to connect the handset to?

Thank you in anticipation,

Peter

[russell_w_b]

Originally Posted by petertheorgan

The telephone is in very good condition but sadly the bells are missing ( the clapper and coils are present ) so my questions are

1) is it possible to get the correct bell domes , I was going to ask before I put a wanted in the correct section .

Yes, it's possible. Can't remember if they're bells 1 and 1A or 2 and 2A. Whichever, make sure one gong has an 'A' after it so the pitch is raised a third WRT the other one and you get a nice 'ting-tong' chord. Two gongs the same (both suffix 'A' or both with no suffix 'A' ) sound bland, like a field-telephone (of which the gongs, incidentally, will fit your 312).

Originally Posted by petertheorgan

2) can anybody give me the correct wiring diagram to reconnect it for plug and socket use and tell me the correct terminals to connect the handset to ?

You need to look here. Everything you need to know!

[russell_w_b]

Just checked: they're Bells 2 and 2A. The 2A is pitched at 'C' and the 2A is not a third above, but is a semitone short of a sixth above it, at Ab.

[petertheorgan]

HI Russell

thanks for that , thats really helpful , all done and the phone works ok but I get bell tinkle when dialing out ,
have I missed something silly
I found a pair of bells from a broken more modern phone but i would really like to fit the correct bells ( and dial label ) if possible

thanks for all your help

I will attach a photo to see if it helps

[petertheorgan]

photos

[russell_w_b]

Hello Peter,

If you're convinced your wiring is correct - buzz your BT plug and lead out if you need to - then check the dial-off-normal contacts behind the dial (the ones that make when the dial is rotated and open when the dial is at rest). Using an ohm-meter, check that they're S/C and not high resistance or O/C when the dial is rotated any distance.

If these contacts don't close, you'll get pops in the receiver and / or bell-tinkle, on account of the bell-shunt cmponents not being switched in.

[petertheorgan]

I cannot see any mistakes but you never know if the telephone had been played with before I got it
a couple more photos attached

[siaynoq]

I can tell you Peter is that:

A) You have the wrong dial. That is a number 10 and fits in the 200 series (pyramid) phones although it should work the same.

B) There is a link missing between terminals 2 and 3 on the chassis (to dial).

Also just had a check on your wiring have you a link between terms 3 and 4 on the main (incoming) terminal board? It is also recommended to fit a 'Rectifier 205' between the receiver terminals to reduce 'acoustic shock' through it.

[russell_w_b]

Originally Posted by siaynoq

I can tell you Peter is that A/you have the wrong dial. That is a number 10 and fits in the 200 series (pyramid) phones although it should work the same.

Looks like a No:12 (trigger) dial to me, having, as it does, a trigger pulse wheel on the back. A No:10 is a 'slipping cam', which this one isn't. But both variants were found on 300 series instruments.

[petertheorgan]

Thanks for your help.

I have just looked inside, terminals 1, 2, 3 and 9 are connected to the white wire. There is no link between 3 and 4, is this correct?

[russell_w_b]

Originally Posted by petertheorgan

is this correct?

Wire it like this (drg attached). it should work.

[russell_w_b]

Originally Posted by russell_w_b

Wire it like this (drg attached). it should work.

Just to be clear: the terminals marked 'DS' refer to those on the dial strip, i.e: the long strip of five terminals immediately behind the dial on the top of the chassis.

[petertheorgan]

Thanks Russell.

I will go right through it this afternoon and check it out - it may have some 'history'.

[siaynoq]

And I slap myself (lightly) don't know what I was thinking, yes of course it's a No.12, sorry Petertheorgan I wasn't even drunk to excuse me haha.

The Dial Terminal strip is the one underneath the chassis linking the actual dial.