BT Relate 200 telephone - UK Vintage Radio Repair and Restoration Discussion Forum

dazzlevision · 30th Jan 2020, 11:50 am

BT Relate 200 telephone (in Alpine white, circa 1992, Engineering name: Telephone 5042AR, BT Item Code 87 7926)

Made by Northern Telecom (which took over STC plc), in the UK, in the early 1990s.

I have one of these, purchased from new and I'd like to get it back into fully working condition.

Initially, I had to open up the microswitch which grabs the line when the handset is picked up, and clean its contacts.

The only fault now is that, unless the phone had been used very recently, the “monitor” button doesn’t grab the line when pressed, I have to pick up and replace the handset. Then the “Monitor” button picks up the line when pressed and the red indicator illuminates. I see from www.britishtelephones.com/t5041.htm that this might be a design fault...?

There also seems to be rather more background noise when compared to other phones connected to any BT sockets on our internal house wiring.

Are there any "stock faults" with this model and is a circuit diagram available? I've looked online, but there doesn't seem to be much detailed information on it. It uses a large DIL (STC custom made/programmed?) IC.

Any information gratefully received!

30th Jan 2020, 11:50 am	#1
dazzlevision Dekatron Join Date: Sep 2003 Location: Near Swindon, North Wiltshire, UK. Posts: 3,608	BT Relate 200 telephone BT Relate 200 telephone (in Alpine white, circa 1992, Engineering name: Telephone 5042AR, BT Item Code 87 7926) Made by Northern Telecom (which took over STC plc), in the UK, in the early 1990s. I have one of these, purchased from new and I'd like to get it back into fully working condition. Initially, I had to open up the microswitch which grabs the line when the handset is picked up, and clean its contacts. The only fault now is that, unless the phone had been used very recently, the “monitor” button doesn’t grab the line when pressed, I have to pick up and replace the handset. Then the “Monitor” button picks up the line when pressed and the red indicator illuminates. I see from www.britishtelephones.com/t5041.htm that this might be a design fault...? There also seems to be rather more background noise when compared to other phones connected to any BT sockets on our internal house wiring. Are there any "stock faults" with this model and is a circuit diagram available? I've looked online, but there doesn't seem to be much detailed information on it. It uses a large DIL (STC custom made/programmed?) IC. Any information gratefully received!