[Motorola] TLN2660a Amplified Speaker info needed

[Geoff Fors]

This is the external speaker for Motorola's original line of cell phones
from the early 1980's, the Dyna-Tac series.  The speakers were accessories
for the 4000X and more deluxe models, i.e. those with the small handsets.

The model breakdown is as follows: TLN 2660A = speaker only, no vsp.  TLN
2661B= VSP speaker, all except 4000XM series.  TLN 2005B = VSP II,  TLN
2008A = VSP II.  VSP means vehicular speaker phone.  Speakers with VSP have
extra circuitry for the hands-free microphone, which plugs into a jack on
the top of the speaker housing.  Those without, have no jack.

There should be a 12 pin molex male on the end of the cable, not a 9.  The
pins you would be interested in, with the wire color codes, are:

- (4) BROWN- Ground
- (5) RED w/Black Tracer - A+ 12VDC
- (8) GRAY Shielded - RX Hi Direct
- (9) GRAY w/White Tracer - RX Hi to VSP board
- (12) SHIELDS - Ground

The speaker contains a rather complicated 1970's design audio amp and
processing circuitry consisting of an op-amp driving a Darlington pair of
push-pull transistors. There is no output transformer; the speaker is driven
through a 350 mfd capacitor.
The speaker was intended to take earpiece level audio and bring it to
speaker level audio.  If you were intending to use it as a power speaker,
you may have to go inside and inject your audio downstream from the original
input audio stages to keep from overloading it.  One possibility might be
injecting the audio through a capacitor to pin 8 of the quad op-amp driver
IC, which is the smaller IC in the middle of the circuit board closest to
the cable connections.

Geoff Fors