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Replacement induction coils.

Started by dsk, October 11, 2012, 08:29:09 AM

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dsk

Today I discovered something which may be common nowledge.
2 of the 3 most common anti sidetone circuits are actually two of a kind.
The W.E. 302, the most copied circuit ever? and the AE40 looks quite different, but are actually the same.  Changing the coil may require changing the capacitor but it not always, just try and decide after a listening test.

dsk

paul-f

Good observation!

Check out Chapter 17 of Old Time Telephones! by Ralph Meyer, for the evolution of common battery anti-sidetone circuits.  Page 145 (2nd edition) is titled "Automatic Electric's Western Electric-type Circuit."

Ralph states that AE adopted the WE circuit around 1940 and used it in the 40-series sets.
Visit: paul-f.com         WE  500  Design_Line

.

dsk

I have to get my fingers into that book.  :)
I think the oldest Norwegian phone using that circuit was put in production in 1932 or 1934 by EB (Elektrisk Bureau). The last one was probably made in 1967, so it had a long life in Norway.
(Western Electric was shareholder in an early period)


dsk