Thread: Mystery unit
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Old 18-10-14, 11:42
Chris Suslowicz Chris Suslowicz is offline
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Join Date: May 2007
Location: England
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Quote:
Originally Posted by cletrac View Post
What wireless set is this unit used with?
None.

It's "Unit, Signalling, V.F., No.3 Mk.II (YB/YA.3814) or Mk.III (YB.02227)" and converts low frequency signalling currents (i.e: magneto ringing) into 500Hz interrupted at the signalling frequency (and vice versa).

It's used for signalling over a repeatered audio frequency or carrier telephony circuit, and is inserted at the 2-wire audio portion (i.e: the local and remote ends).

Someone has removed the data plate from top left, and it's missing the outer wooden case that has a circuit diagram screwed to the lid.

Chris.
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