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Common Western Electric "Solid-Back" Transmitters and Cups

Started by dencins, April 29, 2011, 09:56:12 AM

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WECo actually had five faceplate configurations over the life of the solid back transmitter.

First was the beveled edge that is hard to find today.

In 1895 the 2XX with the heavy ribs on the back was introduced for 229 and 250.  The are usually nickel plated.

In 1917 the 3XX was introduced for the 323 but it originally had screw holes to accommodate the 2XX diaphragm springs (229 and 250 were made using this faceplate for replacement market).  Again many of the early ones were nickel.  I have seen these painted black but do not know if it was done later.  I have seen some painted black that when the paint is removed they are nickel under the paint.

At some later date the screw holes were eliminated.  Some of these are nickel and some are painted black.

As it neared the end of product life a final version came out usually found on 337 and sometimes on 323.  These only came painted black.

Here is a picture of four of the faceplates.



This shows the module adjustment screw.  The picture is of a refurbished 2XX but the 3XX adjustment screw is in the same location on the 3XX bridge.

Once the screw is loose just push or lift slightly on the module post to adjust sound then tighten the screw.



The White transmitter, more commonly known as the "solid-back" transmitter, was developed in 1890 and used from 1895 until the mid-1930s with a few design improvements along the way. 

Versions of the White transmitter were used in small numbers throughout the early 1890s but did not become standard until the 229 was introduced in 1895.

The 229 was followed by the introduction of the 329.  The 329 was similar to the 229 but was insulated.  It was not the first insulated transmitter made by Western Electric, but became the standard in 1913.

The 323 was introduced in 1917.  It represented a significant design improvement over the previous versions.  The design eliminated the two side springs and the screwed on diaphragm, using one central spring that held the diaphragm.  The 353 was a version of the 323 used for mounting on a bracket.

The 337 was introduced shortly thereafter in 1919

Transmitters had different numbers for a varity of reasons.  Some referred to the electronic qualities of the transmitters, with some transmitters used on inter phones, while others were designed for longer lines, etc.  some numbers referred to the type of mounting bracket or arm the transmitter was mounted on.  Whether or not a transmitter was insulated or not was another variable.

A transmitter's intended function did not necessarily dictate where it ended up.  Desk stands were sold by Western Electric without transmitters or receivers.  Older transmitters and receivers were also available as an option.  Repairmen would likely use whatever transmitters were available that would work with a certain phone, so if a desk stand"s 229 failed, it would be replaced with a 250 if that was all that was on the truck.  The later practice of refurbishing candlesticks and wood phones led to all types of combinations.

Sometimes transmitters had their designations changed, in which case the old number was obliterated and a new number stamped beside it.

Evolution of Western Electric Tag Schemes (according to my theory probably wrong)

Western Electric transmitter tags went through a number of changes over the years they were manufactured (mid 1890s to mid 1930s).  They started simply and became more and more complex as the patent dates were taken from the back of the cup and put on the transmitter tag.  This was most likely an expedient so that the repairman just had to switch the faceplate, and not the cup as well.  One consideration when matching a transmitter to a transmitter cup is to make sure there is only one set of patent dates on the transmitter and cup.  Early transmitters had no patent dates on the banana tag because the dates were on the cup.  The later cups had patent dates on the tags but none on the cups.

"W" vs. "*"

The use of the "w" is usually associated with non-Bell System phones.  There are enough examples of "barn fresh" phones with "PROPERTY OF THE AMERICAN BELL TELEPHONE COMPANY" stamped on the transmitter cup and "229w" transmitters, however, to suggest that they were used on some Bell System phones as well.
Another factor to consider is the ratio of "*" transmitters to "w" transmitters.  There seems to be many more "w" transmitters.  Considering that only 10% of WECO business was outside the Bell System, and that Bell was well on its way to monopoly status, that ratio seems off. 

Initially most transmitters were used on local battery phones powered by wet cell batteries that were present in the customers home.  These required a low resistance transmitter.  Common or central battery phones required a high resistance transmitter.  The low resistance transmitters were designated with a "3" on the back of the carbon plunger and had no "*".  The high resistance transmitters were designated with a "7" on the back of the carbon plunger and two "*" marks on the number plate.  In the Bell System, all low resistance transmitters were eventually phased out and only high resistance transmitters were used, making it unnecessary to use the "*" marks on transmitters anymore. 

The Bell System was a complicated entity in the early 1900s, made up of numerous smaller companies with varying degrees of independence from The American Bell Telephone Company.   How these companies sourced their parts may have an effect on this but no one really knows.  The use of the asterisk seems to be used exclusively by the Bell System.  Personally, I think no one really knows for sure.

These are uncommon, they were used on 301A and other phones in the early 1900s.

*A.B.T. Co.*
A scarce transmitter designation used in the early 1900s, stands for American Bell Telephone Company.  Examples that I know of were used on 301A and 293A wall phones.

An extremely rare 229w transmitter found by wds.  A number of entities were known as West Texas Telephone Company over the years, so it's origins are unclear.

WT&T was a holding company within AT&T from 1902-1911.  Not much is known about this apparently very rare transmitter.  It was found out of context on a "Frankenphone" but appears to have once been installed on a wall phone.

Commonly found on a variety of phones, although originally intended for desk stands.

WESTERN ELECTRIC COMPANY all one size no model number.  Uncommon. Two examples I know of were found on 2-boxers, another turned up on a TYPE 22 candlestick.  I think these are early transmitters that "fly under the radar" with collectors because they aren't that distinctive.

WESTERN ELECTRIC COMPANY with the model number below the words.  "COMPANY" is the same size as "WESTERN ELECTRIC".

WESTERN ELECTRIC COMPANY (smaller letters)  "Patent Applied For" below, model # above.

WESTERN ELECTRIC COMPANY (smaller letters)  "Patent in USA JAN 14, 1913" below, model # above.

WESTERN ELECTRIC MADE IN USA (smaller letters)  "Patent in USA JAN 14, 1913" below, model # above.

PROPERTY OF AMERICAN TEL & TEL COMPANY, model # in the center,  "PAT in USA JAN 14, 1913" below
Greg Sargeant
Providence, RI
TCI /ATCA #4409


Earlier Transmitters

Early speaking phone transmitter Craig Stanowski collection

7-digit-Bell System found wall phones and candlesticks

Although these are not the earliest Bell System transmitters they are the ones more commonly seen, and within the range of the average collector.  These are found on two-boxers and fiddlebacks, #10 and TYPE 22s as well as other models, including later phones. 

*A.B.T. Co.*-Bell System candlesticks and wall phones.  These are scarce and command a premium among collectors.


WESTERN ELECTRIC COMPANY found on earlier two-box wall phones
Greg Sargeant
Providence, RI
TCI /ATCA #4409


200 series

200-series transmitters are usually associated with nickel plated candlesticks such as the 20-B or wooden wall phones such as the 293A.  They are mostly uninsulated, and have springs and a thin central screw that hold the diaphragm in place.  They tend to follow the design patented in 1891-92, although there are exceptions.

Looking at the 1908 catalog it appears that the 229 and 250 were the most widely used transmitter, on telephones, RR apparatus, police phones etc.  The 229 was used on candlesticks and wall phones, the 250 was only used on wall phones, especially those with a #10 arm. 

*225*-Used on speaking tube telephones
226w-Low resistance transmitter without lug
227w--Low resistance transmitter with lug
228w-High resistance transmitter without lug
*229*-High resistance transmitter with lug. Bell System central battery candlesticks and wall phones as in the case of the beveled edge example above.
229w-High resistance transmitter with lug. Bell System and independent central battery candlesticks and wall phones, RR apparatus (1908 catalog)
232w-switchboard. Has a larger diaphragm and longer bridge than other WE transmitters
234w-Operator's chest transmitter
242--"Common Battery Bracket Set Transmitter" as used on early Type 85 "fiddleback" wall sets c. 1898-1903.
244w-No.1 Handset
*250*-Bell System phones using the #10 transmitter arm (301a, 317)
250w-Bell System and independent central battery phones using the #10 transmitter arm (301a, 317) as well as others.
251w-Low resistance bracket type transmitter
255w-Used on the 20Bc candlestick
256w-Test set
257w-No. 2 Handset

*259*/259w-uninsulated standard size.  Found one on a #5 arm

269w-Small insulated case for interphones like the 20T and 20P
270wHigh resistance bracket type-transmitter with insulated case.  Wall telephones that require a bracket type-transmitter.
271w-High resistance type-transmitter with insulated case and lug.  The 20-P desk stand and 293A wall phones.
272w-High resistance type-transmitter with insulated case and lug and two 5 1/2 inch cords Wall telephones (except intercoms) that require a lug.

273w-found on a magneto/top box converted to a wall phone.  Also spotted on a WE compact intercom with watchcase receiver.

277w-Used on Interphones like the 293AG

280w Found on a 20-AG RR apparatus

284w-Looks like a typical transmitter, insulated.  Found on portable magneto boxes and "PUSH TO TALK" type phones.

291w-Used on early 20xx series candlesticks and 333 wall phones.
297w transmitter used with metal wall sets

Greg Sargeant
Providence, RI
TCI /ATCA #4409


300 series

300 series transmitters can be found on black finished candlesticks such as the 20-AL and metal wall phones like the 533.  Nickel versions are common as well, used on the 20-PC and 20-BC candlesticks.  Combinations of black and nickel parts are commonplace.  300 series transmitters generally are of the design patented in 1913.  They are mostly insulated and feature the diaphragm with the dimpled center and sticky gasket instead of springs.  There are lots of exceptions to this description.  Dial candlesticks feature later transmitters such as the 323 and 337.

302w-Smaller transmitter found on interphones
303w-Smaller transmitter found on interphones
305w-Smaller transmitter found on interphones
*311*-Found on intercoms and 333 wall phones
311w-Found on intercoms and 333 wall phones


323w-Insulated with lug.  All-purpose: Found on deskstands, wall phones and Interphones

325W-Used on the 327H intercom, older type with retaining springs
329-High resistance insulated transmitter with lug.

*329*-High resistance insulated transmitter with lug.
329w-High resistance insulated transmitter with lug.
337-Common on later candlesticks and 533 wall phones
*350*Bell System high resistance bracket type transmitter for phones that require a bracket such as the 317
350w-High resistance bracket type transmitter for phones that require a bracket such as the 317 wall phone
353w-??? Found one on a NET&T 301A

386w-Operator's chest transmitter

389w-Large transmitter found on candlestick microphones

w/out number and a 1916 patent date.  The example I know of was plated in nickel.

Gamewell marked Western Electric transmitter
Greg Sargeant
Providence, RI
TCI /ATCA #4409


WE made a wide variety of cups to accommodate the different transmitters they used on their phones.  They were nickel plated and painted black.  Some were holed, others were not.  Some were two piece while others were a single unit.  Some were notched and others had holes for the transmitter screws.  This is by no means comprehensive (or factual) but I will attempt to sort through some of the more common types in my collection and elsewhere.

***One consideration when matching a transmitter to a transmitter cup is to make sure there is only one set of patent dates on the transmitter and cup.  Early transmitters had no patent dates on the banana tag because the dates were on the cup.  The later cups had patent dates on the tags but none on the cups.***

Earliar Types:

The early cups were designed to be interchangeable with the several types of transmitter arms and,  later,  the mounting bracket for 20-X series and earlier candlesticks. 

Here is an early type that showed up on a Frankenphone sold on eBay recently:

It has patent dates that refer to Bell's original patent, meaning it was made in the early 1890s.  This is one of the earliest types of transmitter cups used by the Bell System.

Early patent date type.  Note the round hole in the center rather than the notched hole found on later types.  These were used on solid transmitter arms that had the wire alongside and earlier candlesticks (???) They can be found in original nickel or black over nickel and would have been used from 1902-1906.

Similar to above only with the later hole.  The hole was redesigned to more easily accept wires,  most likely when the hollow transmitter arm was introduced.   This does not have a second hole, which indicates that it was from a wall phone, not an early candlestick.

Later patent date type used on 20-X series candlesticks or solid transmitter arms from 1908-1909.  The phenolic grommet is still intact.

Holed with the ABT markings but no dates, probably used from 1909-1912.

Interphones, railroad apparatus and non-Bell System phones had either just the dates or nothing at all:

Middle (?) patent dates without Bell markings.  In use 1906-1908.

Same as above without hole

Used 1908-1909

Holed, without the dates or Bell markings

Same as above without hole used on solid transmitter arms.

Some early cups were refurbished during the depression for use on later candlesticks like the 20AL or 51AL.  They were riveted to hollow brackets and the screw holes were notched for easier servicing.  These are found with a variety of transmitters.  They are re-painted black.

Greg Sargeant
Providence, RI
TCI /ATCA #4409


Later types

Later types found on the 20-XX series candlesticks and later were one piece.  By this time transmitter arms were out of fashion and smaller mounting brackets were used on wall phones.  The 300 series insulated transmitter was introduced and the 200 series uninsulated transmitters were being phased out. 

Typical 20-XX series candlestick cup with ABT markings and no dates.  This one is correct for a 20PC.  Most were black.

Same as above with "PATENT APPLIED FOR" markings

This came off an Interphone that used a 229w transmitter.

Same as above without the hole.  Came off an Interphone with a 323w transmitter.

Not really sure about these, they came in brass and steel
Greg Sargeant
Providence, RI
TCI /ATCA #4409


Greg Sargeant
Providence, RI
TCI /ATCA #4409


First one of these I've seen. 


Quote from: wds on October 19, 2016, 08:22:52 PM
First one of these I've seen.

It is similar to the 229, but used on transmitter arms on wall sets, such as 301A and 317. (acc. to my notes)


Yes, I meant the fact that it's bevel edge *250*.  Unusual.


Greg Sargeant
Providence, RI
TCI /ATCA #4409


No, I missed this one.  Sold on a BIN for $75.  Having trouble finding the listing right now.

Found it!  I'll shorten the link when I have more time.

Wish I had been the person who bought this one.  In the past I have used old 250 transmitter to repair the more popular 229 transmitters.  But with the phone prices dropping as much as they have recently, the 229's are pretty cheap now. 


Looking for some information on transmitters...

I have a *228* transmitter and a 229W transmitter. What does the chart below mean when it says with or without lug?

Which transmitter is considered to be the best and why?