Discovered on
eBay --
A chance to acquire a small proper Strowger exchange which can be handled by one person -just - but better with two..
A very rare version of the 50 line Type 111 PAX previously known as the 50/7A.
Provided with 50 pairs of 600 type L & K relays. All the circuitry uses 'circuit elements' straight out of Atkinson's 'Telephony' - same as those used in the GPO's 2000 type Strowger selectors.
The relays in the PAX are dated between 1960 and 1970 - selectors a year or two earlier. Ringing & tones are normally provided by vibrating relays - the whole exchange running of 50 volts DC.
However this PAX has had electronically produced tone fitted with the ability to change over to the original vibrator produced tone.
Few PAXes had the facility for tie-line working fitted but .........................
How was it done? This PAX has the selectors/connectors fitted with a 'TL' relay indicating that the selectors can be used as an ' impulse repetition bridge' for working over 'tie-lines' - the equivalent of 'junctions' to another exchange. The tie-line/s occupied the last one or more outlets on a level and hence had a two digit access code.
BUT EVEN RARER is the fact that these selectors could also be fitted with NPA or NPB springs and a little screw which operates the NPx springs on a particular level - thus providing single digit tie-line working. Thus you could have 'outgoing' circuits on 1, 9 and 0 simulating a public exchange -
Ideal for connecting to CNet - the Collector's telephone Network which emulares the GPO in early days f STD - all free to use! See www.ckts.info/192/uk
The PAX is also fitted with all ten levels of contacts - unlike the 25 line model which ony has Levels 2 through to 6. Thus you can have extensions on other levels. However by moving the collars around which support the banks, you can lift them to provide Levels '6' through to '0'. Hence you could have tie-lines/junctions on Levels 9 and 0 to simulate codes on a PABX or even CNet.
Another rare feature of this PAX is the extra panels and frame which have been temporarily been removed making transit easier. It mounts on top of the PAX to provide accomodation for extra circuitry.
Complete with front and rear covers. All you need is 50 volts (four small alarm type batteries) and a Krone Connecting box with fve Krone strips (or other terminating box/strip) as the cable from the PAX internal tag strips to an external termination box is still in situ.
Copies of the relevant AT&E circuit diagrams and photocopy of the manual provided..
Just £850-00 as a "Buy It Now".
http://www.ebay.co.uk/itm/Rare-AT-E-50-line-Strowger-PAX-Telephone-eXchange-Single-Digit-Tie-Line-Working-/201511466139
