Overall Switch Setup

An overall view of the SXS Switch. Top contains meters to monitor frequency, voltage, amps. and low&high voltages (alarm relay). Next from top is the Connectors which collects the last two digits dialed and sets up the connection to the called number and provides a talk circuit and ringing and busy tones. The next row contains the Line Finder start selector, Line Finders and First Selectors. When making a call the Line Finder connects to the originating line operates the First Selector and provides dialtone. The First Selector generally using the first digit dialed connects the caller to either a Connector or trunk or Operator circuit if provided. Dialing a bad first digit generally causes the First Selector to return fast busy (reorder) to the caller. The next horizontal relay strips contain the line and cut-off relays for each wired telephone line. Below that is the test and power equipment. On the upper left is the fusing and tone sources for the switch.

 

This photo expands nicely to high resolution.

 

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