[sci.electronics] Telephone Pickup Devices

benfeen@ddsw1.MCS.COM (Ben Feen) (04/30/89)

I recently purchased a $2.00 telephone pickup (suction cup type - stick it
on back of the handset) and discovered that it refused to take audio signals.
I hooked it up to a small portable amplifier.  Through trial and error,
I found that it seemed to react to appliances.  How do these things work ?
Please post answers as mail has a habit of  bouncing off me.
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wheels@mks.UUCP (Gerry Wheeler) (05/02/89)

In article <3412@ddsw1.MCS.COM>, benfeen@ddsw1.MCS.COM (Ben Feen) writes:
> I recently purchased a $2.00 telephone pickup and discovered that it
> refused to take audio signals.  How do these things work ?

They are just a coil of wire.  The idea is that they get placed next to
the electromagnet in the earpiece of the handset and get a voltage
induced into them.  However, in recent years, the phones have been using
a more shielded speaker, so not enough magnetism leaks out to be picked
up.  This is also a problem for people with hearing aids with inductive
telephone pickups. 

You could try locating an older style earpiece to use in your handset. 
You could try getting an older one from the phone company -- they have
them around for people who have the above-mentioned hearing aids. 
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