8J Apparatus Unit WE 1964

[allnumbedup]

I got this item in an online auction.  The auction pictures were kinda of bad and I thought the item next to it was included. Instead I got only this and do not know what it is.  It has a very bulky switch hook for a G1 Handset. Dated 1964. Upon testing, it rings and transmits but the receiever element is connected to the network in a non-standard fashion and jumpers are installed to F and L1 and across the large connecting block but not far off of a residential 500 type phone. The network is unlabeled but doesn't look unusual. The case is heavy steel and the blank front panel slides off while the whole unit looks like it is made to slide into a nook on a piece of larger equipment. The handset was very griming like it got high traffic usage. I am guessing maybe it is a monitoring station for a key system or switching panel.

[rdelius]

Possibly out of a police or railroad call box . Note it has a protector.

[G-Man]

Familiar?

A 17-page BSP on the 570-series (including the 8J apparatus unit) is available for download from the TCI Library.

[G-Man]

Here is an earlier, slightly different version of the 570 set.

[G-Man]

Here is the schematic showing the factory wiring:

[allnumbedup]

Thank G-man. I was able to find the BSP document which states "In order to increase the reliability of the reporting system, the line conductors and S70-type telephone sets (including the handset and cord) are electrically supervised by the emergency reporting line circuit. Any break in circuit continuity, grounds, or crosses will operate a visual and audible trouble signal at the fire switchboard. Although most installations are intended for originating service only, some types of sets, as furnished, are equipped with a ringer."