"hugh_davies.WGC1RX"@Xerox.COM (11/16/88)
I have managed to scrounge an old BT 'Auralite' headset (the hearing-aid sort with a tiny voice-pipe mike) which I want to use with radio gear. Since the whole thing is sealed up (ultrasonic-welded, by the look of it) it's not possible to get at its guts. What I want to do is make up an interface unit with a standard BT 4-circuit jack socket (the headset is fitted with a jack plug instead of the new cheapo plug) so that I can plug in either this or a different handset of some variety. From the rig's point of view it should look like a speaker-mike; from the headset's, the rig interface should look like a phone socket. Designing the interface obviously involves providing power for the headset and extracting the mike signal at the same time as feeding the speaker signal to the earpiece. What I need to know is the pin assignments of the 4-circuit jack plug, and the signals or voltages, etc. that are expected on the 4 lines. The Phone Man can't help; all he's trained to do is install the things (thus demonstrating the value of Education over Training, I suppose). The Phone Shop haven't a clue. I am at my wits' end with this. Any suggestions will be gratefully received. Thanks, Hugh Davies (P.S. 'BT = British Telecom') ==================================== Huge.wgc1rx@Xerox.com