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Old 26th Oct 2019, 11:26 am   #8
midshires
Triode
 
Join Date: May 2007
Location: Northampton, UK.
Posts: 36
Default Re: A Slightly unusual Candlestick Telephone

I know exactly what your telephone is!

I sold one of these at the Avoncroft swapmeet earlier this year for £100. In fact that telephone you bought may well be the same one!

The photo of the paster diagram is too small to see well but if the of the line cord terminals are marked A, B, BZ and R, then that clinches it.

Your telephone was sold by the Relay Automatic Telephone Company for use on one of their small PAXs (private automatic telephone exchanges) that worked on the three-wire system. GEC was another manufacturer that used three-wire telephones on some of their PAXes. In this system DC (rather than AC) was used to ring the telephones. The ringers were trembler bells and the ringing current was sent over a third wire, with the return over one of the line wires. This system is quite clever, as it means you don't need a vibrator or ringing machine to generate AC and telephones do not require a blocking capacitor. Of course, it does mean that the system requires an extra conductor in the line wiring and the use of non-standard telephones, but despite this, the system was more economic than conventional telephones, meaning it was attractive to cash-strapped users. Three-wire telephones continued to be manufactured by GEC well into the 1960s, and three-wire/battery ringing 706s turn up from time to time. In fact, at the Milton Keynes swapmeet a week ago, Chris Elliott sold a three-wire Gecophone to a THG member who actually has a three-wire Relay PAX, so it went to a good home.

The ST manufacturer code stands for Sterling Telephone and Electric Ltd of Dagenham (see Bob's website at https://www.telephonecollecting.org/...ling/Intro.htm ). Sterling made a lot of telephones for the Relay Automatic company.

You can of course use the telephone on a conventional two-wire telephone line, but you will need to provide a conventional AC ringer and capacitor across the A and B wires.

I have attached photos of the paster that was in my 3-wire Relay candlestick (it looks identical to your one, with the bellset dotted), also a photo of the same telephone with its proper bellset (a Gent's dome DC bell on a block of wood). The dial has been replaced by an ATM type 24C (ATM also supplied telephones to the Relay company).

Hope this helps,
Andy.
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