L/DTC
London Datel Test Centre
The London Datel Test Centre at the Tower.

Colin Atkinson, working at the time for London East Datacomms, recalls a visit in 1976 to check out the test equipment...
| EXIT | L/DTC |

I started work on data communications in London East Area in 1970 and at that time we had to commission all new modems installed to the Datel Test Centre. By 1976 many more circuits were being installed and some customers refused to pay for PSTN lines to be fitted as standby for their modem private wires, so we looked at building our own test centre within East Area.

To see how the test centre was constructed, we visited the Test Centre at the Tower, hence the photographs. Later on, in the 1980s, the Datel Test Centre was moved from the Tower to another location within London Centre Area.

Datel Test Centre
Datel test equipment
[1] Oscilloscope [2] Datel Tester 1C [3] Pigeon Holes
[4] LMS 5A/Oscillator 98B [5] Key & Lamp Units [6] Frequency Counter 1000F

Note the metal framed chair with arms and a patterned green cover, so typical of the era.

Colin writes...

"From what I can remember, the equipment is as follows (left to right)..."

  1. An oscilloscope (number not remembered) to check frequency formation.
  2. A Datel Tester 1C - Which is used to carry out customer data simulation tests to an engineer with a similar tester connected to the customer's modem. At that time the highest speed modems we had were 2,400 bits/s. And these could not work at that speed over the public switched network. We did also have some 48k/bit modems, but they needed a Co-Axial circuit to be installed to the customer's premises.
  3. Pigeon Holes.
  4. On the left side (the meter with 2 knobs underneath) is a Level Measuring Set No 5A (LMS 5A) to measure received signal strength. On the right side (the meter and large circular dial with central knob) is an Oscillator 98B signal generator which can be set to a specific output.
  5. A Key & Lamp Unit.
  6. Under the pigeon holes is a Frequency Counter 1000F, which was used to measure the frequency transmitted by the modems
Design, images and text compiled by © Light-Straw. With thanks to Colin Atkinson.
Page last updated 30th July 2011. Checked July 2024.

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