21 May
2009
21 May
'09
12:16 a.m.
Ethan Dicks wrote:
I'm unfamiliar with Automatic Electric. Did they
make home phones or
commercial?
Chuck beat me to the reply while I was composing, but anyways:
Going from web info, their lineage goes back to
Strowger and the first automatic exchanges. Competitors to WE, manufacturing a
range of equipment to supply to independant phone companies. Bought up by GTE
(another WE competitor) in the 50's.
Which explains why the phone (1-tran DTMF) sitting beside me on the desk here
is from AE: GTE used to own BCTel (British Columbia Tel).
happened to look like a telephone. I was surprised he
was able to do
that, since my experience tearing apart phones as a kid was the
1-transistor design that I didn't understand at the time, but when I
saw he had an IC-based keypad to work from, how he did it was clear.
I don't recall when I saw my first TouchTone phone
(besides the ones
at COSI, the local science museum, in the Bell exhibit), but probably
not until the late 1980s.
Those don't correlate do they? (tearing apart TT phones as a kid but not seeing
a TT phone until the late-80s?)
I am enjoying exploring the nuances of the
1-transistor design, but
I'm sure I don't fully appreciate how it works yet. The IC-based DTMF
generators are somewhat obvious to me at least.
I picked up this one somewhere back around 2001, recognising from style and
exterior simplicity (no extra functions like redial or stored numbers) that it
would be a fairly early TT. Thought it would be interesting to see how the DTMF
was done, opened it up to draw the schematic. While I was expecting discrete
(accurate), I was quite surprised to find the novel simplicity of the
1-transistor circuit.