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OT-What is a Western Electric 20-T?

Started by Sargeguy, March 20, 2011, 10:05:46 AM

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Sargeguy

15 minutes of furious googling has left me in the dark.  I found one rigged as an intercom, and I know there is a site that lists 20-series variations, but can't seem to find it.



Just won it on eBay, I am a sucker for nickel!!!
Greg Sargeant
Providence, RI
TCI /ATCA #4409

Sargeguy

#1
While we are at it, what is a 20-S???



Didn't really need one, but it was only $26 and change from the same seller.  Actually this one is easier to track down, it is a black painted version of the 20B.
Greg Sargeant
Providence, RI
TCI /ATCA #4409

Phonesrfun

I don't know, and my usual source (Larry Wolff's book) is unusually silent on the subject, but here is what he says:

" The letter designations of the desk stands specified the purpose for the stand, and, in effect, the type of transmitter, receiver, and internal switching accomplished by the switch hook.  The author feels it of no great importance to discuss these letter designations in great detail.  Most desk stands have been up-graded since their manufacture and are not found with the original components.  For example, local battery telephones were converted to common battery sets, PBX sets and later into telephones compatible with big city automatic exchanges."

The latter part of what he says is consistent with some of the wild variations I have seen in hookswitch configurations, even on my small collection of desk stands.

You might be able to find more information from the TCI listserve.  I think there are some avid stick collectors there.
-Bill G

bingster

I see the 20-S listed in my information, but it doesn't say what it's for.  It just says it's a "regular type" (as opposed to a back contact or cutout button set).  It does, however, say it's a black set, and yours clearly is nickeled.  That's from AT&T 3851, March 1917.

I have a feeling that you'd need an older book to get a good answer on that one, and on the "T".
= DARRIN =



Sargeguy

#4
Thanks.  The 20-S is a black-painted 20-B according to a couple sources I found Googling.  This makes sense since the hook appears to be black.  It used a pony receiver.  I assume the 20-S is older because of the solid perch and that it is an equivalent to the 20B.  The later perch and apparently original 143? receiver would put it a little later (I assume)

I posted the query about the 20-T on the TCI list but so far no one has responded except the guy who sent me a link to an auction for a  CD with old WECO catalogs on it.  

Doesn't the green cord usually signify that it was used as an intercom?  Or am I totally off-base?
Greg Sargeant
Providence, RI
TCI /ATCA #4409

Phonesrfun

I have never heard that green cords equals intercom before, but heck, there's a first for everything.  Do you remember where you heard or read that?

-Bill G

bingster

I've seen many nickeled sets with green cords, so I wonder if it's a possibility that they came with that color cord as standard rather than brown.
= DARRIN =



Sargeguy

Greg Sargeant
Providence, RI
TCI /ATCA #4409

GG



Having never worked on these before I'm going to risk a foot-in-mouth maneuver and suggest the following:

IF the phone has a carbon transmitter of any kind, and the hookswitch has at least one working contact that opens when hung up, then it can be connected to a subset or otherwise used on a CO line. 

The receiver cordage should at minimum be twisted together into a simple braid; I can't imagine any phone was manufactured with two loose wires flopping around.  The line cord may need the same treatment if it's similarly unraveled. 

If the receiver is not of a type that is meant to have DC voltage flowing through it, it should be connected to some kind of subset that will block DC voltage.  At that point you should also put a varistor or double-diode hookup across the receiver terminals to protect both your ears and the receiver diaphragm (I can't imagine that modification would be controversial). 

You can use it as an answer-only phone or hook up a touchtone dial in a plastic housing, to the subset; though that modification might elicit some sighs.  As a matter of fact there is a voice-recognition dialer available for about $250, that could be used instead of a touchtone keypad.  It's made in Israel and sold via online stores that sell accessibility tech for disabled folks.  It plugs into the phone line in series with the phone. 

The latter option suggests an interesting project that could be done by Asterisk and C*Net folks with the relevant programmer skills: 

A voice recognition dialer that only handles the digits 0-9 and * and # and "pause" (for example "star seven zero pause (followed by a phone number)..."), and "emergency" (speed dial 911).   When it first answers it should say "Number, please?" in a traditional operator's voice, and then "one moment please" while outpulsing the digits to the line.  It should enable hookflash to "recall operator" and then it should say "operator" and recognize the word "flash" to send a flash signal to the CO for call waiting.  This should be relatively simple compared to other voice rec devices since it doesn't have to interpret names or other words.  It would thereby enable all of the nondial phones we'all have, to be put back into service in original condition, and function in a manner roughly similar to the way they originally did. 

Sargeguy

Thanks.  I will probably switch it out with my 20AL that's connected to a 295A, or else leave it on the shelf looking pretty.
Greg Sargeant
Providence, RI
TCI /ATCA #4409

Sargeguy

Well so far no one has been able to solve the mystery of the 20T, but we have narrowed it down:
-Used with the Western Electric "Interphone" system
-Some were available with intercom buttons
-Both types of perch were used
-143 and 144 receivers are found on examples
-269, 302, and 329 transmitters have been found

Greg Sargeant
Providence, RI
TCI /ATCA #4409

Bill

Sargeguy -

I would think that they would be mentioned in early issues of either the Bell System Technical Journal (BSTJ) or the Bell System Practices. Both are very voluminous publications, though, especially BSTJ. And I can't find a way to do a useful Search on either one. Does anyone know of a multi-volume search tool for either of these?

Bill

Sargeguy

Were Interphones a Bell System service or something separate?
Greg Sargeant
Providence, RI
TCI /ATCA #4409

Sargeguy

#13
Paid for these on Saturday and they arrived today.  The 20-S restoration project is coming along.  The 329W transmitter is incorrect for an original 20-S.  I took off the transmitter and attached an uninsulated cup and knurled nut.  Looking for a 229 transmitter to go with it.  The base was unmarked, and it doesn't fit the descriptions I read of early unmarked WECO bases.  Also, it has been nickeled at some point, which is inconsistent with the black enamel finish of a 20-S.  So I replaced the base and stem with one from a WECO microphone.  I need to paint the perch black, and will probably paint the base to match.  I will keep the transmitter nickel.  I added a pony receiver, which is the correct type for this model.



The 20-T is as found except that I removed the old cords and switched the transmitter with an identical but shinier transmitter from the 20-S.  The nickel is 100% and should shine up nicely.  The 143 receiver has a small chip but looks good otherwise.  The only real issue is the missing base-plate cover, which needs to be green fabric.  Anyone re-covering a pool table? Call me.



Greg Sargeant
Providence, RI
TCI /ATCA #4409