Rotary and Touch Tone

220-, 1220-, 2220-, AC- and AD-types - and variations

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U N D E R C O N S T R U C T I O N
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ON THIS PAGE: Handsets Bases Specialty Sets
Handsets: 220 1220 2220 Bases: AC- AD-
Specialty Sets with Trimline Handsets: Hospital Interphone 50A Transaction Telephone Elevator Design Line

RELATED PAGES ON THIS SITE: Colors Handsets Table Key Development Timeline Touch_Tone_Development
WE 500-Series WE 1500-Series WE 2500-Series WE Design Line

Trimline sets were announced in April 1964 and evolved into the models shown here over the years. They were made by Western Electric until divestiture in 1984, then by AT&T.
Numerous similar designs by competitors demonstrate the popularity of the award-winning design.

To see where the Trimline came from, visit the Development Timeline

The main innovation was placing the dial in the handset -- a new, smaller #10 rotary dial with moving fingerstop.
Users could hit the recall button under the dial to start a new call. No need to "hang up."

Handsets, bases and cords were separately packaged and merged by the installer -- reducing inventory.
The handset contained the receiver, transmitter, dial and network.
A base contained the signaling device (bell) and switchhook.

Cords were plug-ended. Early production used "maxi" plugs. Later sets used modular ("mini") plugs.
Adapters permitted the use of handset cords with mini plugs in sets with larger jacks.

This page is intended to be a quick summary of the Trimline models produced and major functions.
Western catalogs and technical documentation only show the models that were in production or service at the publication date. To understand the full scope of models produced we must compile data from many years of documents.

Each model had suffix letters that defined variations.
Details can be found in the Bell System technical documentation (e.g. BSPs - Bell System Practices).

W	Without Bell System markings
G	Polarity Guard
M	Modular set
CS	Customer-owned (including internal components)

More details on set coding are found on the 500-series page. Many also apply to Trimline sets.

Most info in the chart is from manufacturer catalogs and ads
plus discussions on the TCI and ATCA Email Groups and Facebook sites, and on the Classic Rotary Phones Forum.

TCI Singing Wires articles covering the Trimline include:
[Available on-line in the TCI Members Area]

March 2007 - Trimline Cords by Richard Gerber
August 2008 - Trimline Cord Production by Richard Gerber
May 2013 - Trimline Base Evolution by Richard Gerber and Paul Fassbender
August 2015 - Trimline's 50th Anniversary - Design Evolution and Field Trials by Paul Fassbender

No claim is made regarding accuracy or completeness.

If you're enjoying looking at this level of detail and haven't joined one of the phone clubs yet, see the links page.

If you're identifying a phone, you still need to check the internal components as many phones were refurbed and had internal components changed or removed. If done in a Bell System refurb facility, the code on the bottom was usually repainted or remarked. Many independent shops or field mods were not remarked with the accurate model number.

For color information, see: Phones in color!

This page is a work in progress. Please send comments, additions and corrections.
Thanks for additions from Fred Adler, Steph Kerman and Sam Etler.

Last update: 5 Aug 2019.

TRIMLINE HAND TELEPHONE SETS

Model	Major Functions	BSP
220	Rotary Hand Telephone Set. Early production sets required a 2012-type 6-8v transformer for the dial light. Later production sets had square buttons and used line-powered LED illumination for the dial. Number plates were marked "LED". (See BSPs for details.)	502-303-101 502-303-102 502-320-100 502-320-200 502-322-400 WE Catalog Cards
226	Rotary Hand Telephone Set with 315-type amplifier and volume control in handset - above the dial.	502-303-102 502-322-400
1220	10-button Touch Tone Hand Telephone Set. Dial lights required a 2012-type 6-8v transformer.	502-303-101 502-320-100 WE Catalog Cards
2220	12-button Touch Tone Hand Telephone Set. Early production sets had round buttons, like the 1220 set above. Dial lights required a 2012-type 6-8v transformer. Later production sets had square buttons and used line-powered LED illumination for the dial. (See BSPs for details.)	502-303-101 502-303-102 502-305-101 502-320-100 502-322-400 WE Catalog Cards
2226	12-button Hand Telephone Set with 315-type amplifier and volume control in handset - above the dial.	502-303-102 502-322-400 WE Catalog Cards

TRIMLINE BASES

Model

Major Functions

BSP

Trimline - AC wall base

Wall Base.

Handset shown in the "waiting position" on the top edges to keep the line temporarily open.

AC1: "Permanent" wall type (hardwired).

AC2: "Portable" wall type (modular plugs and jacks).

502-303-101
502-305-101
502-321-100
502-321-400
502-322-400

WE Catalog Cards

AD
Trimline - AD desk base

Desk Base.

502-303-101
502-305-101
502-321-100
502-321-400
502-322-400

WE Catalog Cards

SPECIALTY SET BASES USING TRIMLINE HAND TELEPHONE SETS

Model	Major Functions	BSP
AE	Hospital Interphone Used with Trimline 220-, 1220- or 2220-type hand telephone set. Bases with 3 or 5 keys were made for different equipment arrangements. Part of the 3A Communication System. BSPs show the control console and system wiring.	512-535-202 512-535-100 512-535-200 512-535-201 512-535-300 WE Catalog Cards
50A	50-type Conference Telephone Used with Trimline 220- or 2220-type hand telephone set. Included carrying case and two external microphones. 50A: Early production units had retractable handset cords. No A-lead control. Only one microphone could be active at a time. 50A1: coiled modular handset cord. A-lead control. Any combination of microphones could be active. 4-wire operation possible. "Portable Conference Telephone" Bell Labs Record article: https://www.telephonecollectors.info/index.php/search?q=50a+blr	512-630-110 Issue 1, Jan70 512-630-111 WE Catalog Cards CD- and SD-69900
5000 5100 from a Bell System Ad	Transaction Telephone Used with Trimline 220- , 226-, 2220- or 2226-type hand telephone sets. Includes magnetic stripe card reader and automatic dialer. Optional 5000A dial pad for customer PIN input, selectable TT/DP (Touch Tone / Dial Pulse) dialing. Note: Several models were produced. Later models had K-type handsets. Bell Labs Record article: https://www.telephonecollectors.info/index.php/search?q=transaction+blr	502-323-400 502-323-401 502-323-403 WE Catalog Cards CD- and SD-69926-01
758	Elevator Telephone Black only. Rotary dial. Requires D-95334 Outlet Box and D-95332 Frame	WE Telephone Product Handbook
AL1	Elevator Telephone Base Use with 220- or 2220-type Trimline hand telephone set. When used with a 220A-3 it makes a complete 758A-3 set. Replaces 322B and 758A sets. Also used in corridors and building entrances.	502-330-100 WE Catalog Cards
2322	AT&T Elevator Telephone. Uses a Trimline 210 Hand Telephone Set. Hardwired. Found Set: Box marked AT&T Little Rock, 10-Jul-95	AT&T CIB 3155 i1, Sep92
2942	Director. See details on the Design Line page.	Design Line page
950 2950	Noteworthy. See details on the Design Line page.	Design Line page

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