[sci.electronics] Intercom systems.

joe@dayton.UUCP (Joseph P. Larson) (06/27/89)

I ride a motorcycle.  My wife and I would like to have an intercom system
so we could talk comfortably to each other on our trips.  Looking around,
Radio Shack has an FM transceiver that uses an earpiece as both microphone
and speaker.  A pair of these would work great and would be useful when
we get the second bike, but they want $90 for it.  DAK has something similar
to this, but I've tossed my DAK catalog, so I'm not sure exactly what it is
they have, but I think they want bucks to.

Now, this shouldn't be that difficult, especially if I just want the
intercom feature.  What I need is either a very small microphone or perhaps
a throat mic fed into an amplifier fed into my wife's earpiece and vice
versa -or- an earpiece mic with otherwise the same setup.  I'd prefer to
use an earpiece as the mic, too.

So -- lotsa questions:

1. Has anyone else out there done this before?  Care to share your plans
	with me?
2. Could I just take a microphone and wear it at my throat underneath my
	coat?  This would make it easier as I wouldn't have to mount the mic
	inside my helmet somewhere (I don't care to drill holes!).
3. Does it take a special earphone to also serve as the mic?
4. Anyone have a vox circuit diagram handy?


The basic problem is location of a microphone.  An amplifier is simple.
If I just wanted a simple 2-way intercom system, that'd be easy.  But I
am limited with my mic.  There isn't a lot of room inside a full-face helmet.

Comments?  Any help I can get would be greatly appreciated.

-Joe
-- 
Life is a cabaret (old chum).
UUCP: rutgers!dayton!joe   (Picts 1-13 are   DHDSC - Joe Larson/MIS 1060
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