[VoIP] Audichron information
jnovack at stromberg-carlson.org
Mon Nov 21 08:21:05 CST 2005
This was sent to the TCI list, in case you aren't on that list
Goes into great detail about the Audichrons
Forwarded to the list and Alan from the non-TCI author:
A friend of mine passed along an e-mail you had posted to the Telephone
Collectors International board. He also sent along a picture of your
When I got out of college in 1972, my first job was working for
Audichron in Atlanta. (Actually, it was in Doraville, but they
preferred to use Atlanta.) My job was scheduling the machine shop and
the Mechanical Assembly department.
The machine you are restoring is called a STM. Audichron made two basic
kinds of time announcers: STMs and M-12s. STM is an abbreviation for
"Small Town Machine," and STMs were normally installed solely in small,
rural towns. M12s were for large cities and had more features than the STM.
The time machine has three drums (not two) that rotate round and round.
It also has two sound heads.
Sound head one drops down on the message drum. "Save by the 10th, earn
from the first at Central Brevard National Bank. Central Brevard
Now sound head number 1 comes up and sound head number 2 drops down on
the hour record: "Time two."
Sound head number 2 continues onto the minute record "forty two."
Thus the three records give the entire message: "Save by the 10th, earn
from the first at Central Brevard National Bank. Central Brevard
National Bank. Time two forty-two."
On a STM, the message record could have (I think) 12 different messages
recorded on it. A technician at the phone company had to manually pull
out a pin on the side of the drum and rotate the drum to a new position.
This was done very infrequently (usually for a holiday message) at the
request of the sponsor.
The M12's message drum had 12 messages, and it could advance them
automatically on each announcement. It could also be set to just play
the same message over and over.
The hour record has just 12 recordings on it: Time one, time two, time
three, ..., time twelve.
The minute record has 60 recordings: one, two, three, ... fifty-nine,
The M-12 has TLP, Traffic Load Protection. During peak call times, the
machine would automatically shorten the message so more calls could be
There is a large drum in the middle of the machine. The drum rotates in
a bath of automatic transmission fluid to keep it lubricated. There is
a groove carved in the surface of the drum. Some kind of a pin fits
into the groove and connects to the rod that holds the sound heads.
This is what causes the rod to move left and right so the sound heads
can align themselves with the records. Inside this drum are a complex
series of gears. The gears are what cause the three drums to index to
the proper position each cycle (e.g. change the hour once an hour,
change the minute record once a minute).
The temperature machine has one recording drum. There is a lead screw
on top which holds the sound head. A thermometer was placed on the roof
of the telco office in a "birdhouse." The birdhouse was made of cedar
(I think) and painted white so it wouldn't absorb heat. Somehow the
thermometer was hooked to the temperature machine, and this caused the
lead screw to turn and moved the sound head over the proper recording.
(I think it tried to balance resistance somehow.)
The temperature record typically has 140 recordings on it: Temperature
minus 20, temperature minus 19, temperature minus18, ... temperature
118, temperature 119, temperature 120.
Periodically, someone from the telco central office has to lubricate the
surface of the recording drums with silicone fluid. Otherwise the
friction from the sound heads would wear away the rubber. (They also had
to be careful not to get the silicone on the "Hammertone Gray" paint as
it would eat into the paint!)
Audichron was famous for being able to install equipment in any central
office in the world. Every product has options which were referred to
The basic time machine part number was 5600-L01 [pronounced fifty-six
hundred list one.] As I recall there were something like 30 lists:
5600-L01, 5600-L02, 5600-L03, etc. Depending on what lists you put
together, you ended up with unique machines. You could, for example,
end up with something like 5600-L01,L03, (2)L07, L29. (That's just a
The Mechanical Assembly department was headed by Elbert Jones who was
around 60 when I knew him. It was my job to tell Elbert the kind of
equipment he needed to assemble by telling him which 5600 lists to
combine. By combining different lists, you'd get STMs or M12s or other
variations of the time machine. There were lots of variations including
"Comparator Units" as were found in New York City. These were hooked to
an oscilloscope which monitored WWV over the radio and adjusted the time
automatically. The Comparator Units has three records just like a
regular time machine. However, as I recall, the message record was
where the seconds were recorded so you got a message like: "At the
tone, the time will be one forty-two and 10 seconds." The tone came
from a circuit board. The machine played the records in this order:
Hour (At the tone the time will be one), Minute (forty two) and finally
Message (and 10 seconds.)
Interestingly, Audichron made the announcer for the National Bureau of
Standards to use on short-wave stations WWV in Colorado and WWVH in
Hawaii. So, in New York City, you had one Audichron machine listening
to another Audichron machine in Colorado!
New York City actually had a dual M-12 system. They rented two machines
from Audichron because they received so many calls per day. At 10 cents
per call [message units], New York Telephone couldn't afford to have
their time-of-day service go down for a minute!
The temperature announcer was a 5500-L01 with different lists. You
could get variations by combining different lists. For example, I still
remember machines we built for Parker, AZ and Blythe AZ where the
temperature scale had to go up to 130 or 140 degrees rather than the
normal 120 degrees. We also had to be able to have Fahrenheit and
STM units was normally cabinet mounted. You have a nice STM cabinet.
M12s were normally rack mounted. We made enclosures on which the time
and temperature machines sat in the telco racks. We has 19" -wide and
23"-wide to match whatever the central office needed.
The circuit boards were housed in enclosures that held either 9 or 11
circuit boards (depending on rack width). Some of the boards controlled
the operation of the machine; they would cue the trunks when to answer
the incoming lines. Some were alarm cards that reported trouble to the
central office. (Look for a red lamp cap with "ALM," that's a major
alarm. White lamp caps with "ALM" were minor alarms.)
Most of Audichron machines waited until the beginning of the
announcement to answer the call. A few telcos wanted "barge in" where
the call just started in the middle of the announcement, but the caller
heard announcement after announcement until he/she hung up.
Audichron has a two man Customer Engineering department (Chris and Jim).
These guys worked with each telco on every installation to determine
what they needed. The telco would describe their equipment, and the
Audichron engineers would determine what kind of options and trunks
Audichron needed to build.
As I recall, Audichron has about 30 different kinds of trunks such as
Selector Level Digit Absorbing Trunks (SLDATs). Some of the base
numbers were: 7300-L01, 7260-L01, etc. For each main type of trunk,
there were dozens of options and wiring options that had to be
engineered to meet each and every central office's needs. A typical
trunk might look like: 7300-L01,L03,(2)L05,L20,L23, wrg X,Y,Z,Q. If you
pull out a circuit board from your machine, you'll probably see a white
sticky label on each board that identifies the part number, optional
lists and wiring options. You should also find the sales order number
(e.g., 80-0255 [the 255th order in 1980]) and shipment date. When I
started in 1972, a secretary in my office had to type all of these
labels one-by-one on an IBM correcting selectric typewriter!
We had two people who were known as "talent." They came in on a
part-time, as-needed basis to do recordings. Of course, you know Jane
Barbe. The male was John Doyle who was the weatherman at Channel 2 in
Atlanta. Jane would come in a couple of times a week to make message
records for new installations. She would also make new message records
whenever an end-user (i.e., bank) wanted some kind of new message. Once
a year, Jane would come in to make new "master" hour and minute
recordings to "keep them fresh."
An Audichron installer installed each new system in the telco central
office. He worked with telco installers in the central office. After
the technician went home, it was up to the telco employees to maintain
the machine: lubricate the records, add transmission fluid, change the
message records when their customer (e.g., the bank) wanted them
changed, adjust the machine for daylight savings time twice a year, etc.
Audichron's customer was the telco. The telco's customer was the
bank. Audichron leased the machine to the telco, and the telco leased
it to the bank for a higher monthly fee.
Of course all of the above was before deregulation. Deregulation
changed everything and was actually the end of the mechanical time and
temperature announcers. (Another long story!)
I have attached a photo of the original painting that was reproduced as
a full page in the December 1972 issue of Esquire Magazine. The article
was about Audichron and Jane Barbe. Thought you would find it amusing.
(Let me tell you, the management at Audichron did not like the article
one little bit!!!)
Hope I haven't bored you too much. You brought back a few memories!
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