BT Tribune telephone - UK Vintage Radio Repair and Restoration Discussion Forum

Sparks · 15th May 2014, 8:22 pm

Does anyone know what type of microphone/transmitter is used in these phones ? I am using the innards of one for a project and am having trouble finding a microphone that will work.

Thankyou.

Nickthedentist · 15th May 2014, 9:00 pm

It will surely be either a dynamic one (i.e. moving coil, low impedance), or an electret capsule type (condenser microphone with built-in FET pre-amp). Have you got the original microphone to analyse? The former were more popular in British phones of the 1980s.

Note that like many phones of that era, the Tribune was made in many different versions (pulse, DTMF, bell, tone caller etc.) and no doubt by different manufacturers too, so your Tribune might well be different to mine.

Nick.

Sparks · 15th May 2014, 9:57 pm

Thanks for your prompt reply Nick. The phone is I believe an enhanced Tribune. There is a volume control for incoming speech which is why I bought it in the first place. I don't have the original microphone to hand just now but I recall it being about an inch in diameter and quite heavy for its size.

By the way I checked for voltage across the microphone input and I got 1v if that helps.

15th May 2014, 8:22 pm	#1
Sparks Heptode Join Date: Oct 2006 Location: Leeds, West Yorkshire, UK. Posts: 597	BT Tribune telephone Does anyone know what type of microphone/transmitter is used in these phones ? I am using the innards of one for a project and am having trouble finding a microphone that will work. Thankyou.

15th May 2014, 9:00 pm	#2
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,843	Re: BT Tribune telephone It will surely be either a dynamic one (i.e. moving coil, low impedance), or an electret capsule type (condenser microphone with built-in FET pre-amp). Have you got the original microphone to analyse? The former were more popular in British phones of the 1980s. Note that like many phones of that era, the Tribune was made in many different versions (pulse, DTMF, bell, tone caller etc.) and no doubt by different manufacturers too, so your Tribune might well be different to mine. Nick.

15th May 2014, 9:57 pm	#3
Sparks Heptode Join Date: Oct 2006 Location: Leeds, West Yorkshire, UK. Posts: 597	Re: BT Tribune telephone Thanks for your prompt reply Nick. The phone is I believe an enhanced Tribune. There is a volume control for incoming speech which is why I bought it in the first place. I don't have the original microphone to hand just now but I recall it being about an inch in diameter and quite heavy for its size. By the way I checked for voltage across the microphone input and I got 1v if that helps.