Ethan Disck Wrote:
35Y3D / Apr 1977 - 7 wires as previously described
35AF4A / Jan 1081 - 11 wires as previously described
Yes, there are a couple of different Touch Tone Pads floating around. The main difference
between them is a couple of things. The ones with more wires are designed for use with
SpeakerPhones ("List 3" and the like for those reading BSP's at home). The
extra wires do a couple of things. One set mutes the speaker a bit (an extra set of
contacts) when dialing so you won't get blasted with the tones on the speaker (normal
use is to really send LOUD tones down to the central office). The other wires provide
power to the oscillator when using it "hands free". Normal power is derived
from the telephone line, but with speaker phones, it is a bit different.
Hopefully this will explain things.
My problem is that I have a couple of "solid state" (non-coil) pads (they use an
IC) and they are only compatible with non speakerphone telephone sets. Here at my parents
house, they have three 2565 sets, one which is with a speakerphone. I would like to
replace the old single transistor L-C pads (they turn on tones a bit mushy) with more
modern ones, but they don't have all the wires. One of these days I'll figure out
how to make do. Ackk! another "project"...