354? question

[Kenny C]

Does a 354 have a 4 wire ringer?

[Dennis Markham]

Kenny, any that I've run into (354's) had 4 conductor ringers.

[Kenny C]

Ok thanks Dennis.

[Phonesrfun]

The 304, which is the cousin to the 302, and the 354 wall phone had 4-conductor ringers.  They also had the center-tapped primary 101-B induction coil with the "M" tap, and the extra set or hookswitch contacts.  Apparently, they only made the 354 wall phone in this configuration, and did not make a 352.

The purpose for this extra and more complicated wiring was for automatic number identification (ANI) on outgoing calls from a party line.  It allowed the central office to identify which caller on a party line was making a call.

In order to offer people affordable service, they could get a party line as opposed to a private line.  In addition, for dirt-cheap monthly rat (at the time it was cheap), they also offered you a dirt cheap montly rate, and you were charged for each call on even local calls.  This was called measured service.

The split ringer and the "M" tap on the induction coil allowed them to wire a ground connection at each of the phones on a party line slightly different.  This had no effect on the sound quality of the conversation, but the central office could sense which party on a common line was making a call, and then bill them accordingly.

The 500 series and the 554 wall phone all kept this arrangement with the extra tap in the induction coil, the 4-wire ringer, and a hookswitch that switched both sides of the line instead of just one.

See the schematic of the 354 here:

http://www.telephonecollectors.info/index.php?option=com_docman&task=doc_details&gid=2172&Itemid=11