TXE4 - An Analogue Exchange

In spite of its claims to advanced state of the art workings, the TXE4 was very much an analogue exchange. The processors were solid state, but the rest of the exchange was comprised of Strowger hybrids. Remember, the exchange had to interface with existing Strowger exchanges and the BT network...

Left: "A suite of junction relay set racks. They are all in prompt alarm. This is probably before the exchange was in service so there was nothing on the other end of the junction circuits, hence the alarms. All of these pictures were taken at Manchester Blackfriars, Irwell House."

Photo: TXE4, Manchester Blackfriars, Irwell House © Nigel Pope 1978.

| EXIT | An Analogue Exchange |

An Analogue Exchange

TXE4 was a 'modern electronic' exchange which was developed in an age before personal computers but, it was revolutionary in comparison to the existing Strowger switching equipment.

Over 500 TXE4 exchanges were installed in the UK and they were a key part of the switching network for over 20 years.

TXE4s had to be compatible with:

The older 'loop-disconnect' dial phones
The emerging MF4 'Touch-Tone' press-button phones
Strowger exchanges (Director & Non-Director)
Crossbar TXE2s
Signalling to the Manual Board (AMCs)

	Exchange maintenance TO in the picture. The thing on the trolley is a "portable" tester. The racks contain Markers and SPUs. Photo: TXE4, Liverpool Central © Nigel Pope 1981.

Design, images and text compiled by © Light-Straw. With special thanks to Nigel Pope.
Page last updated 15th May 2012. Checked May 2021.

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