ArticleslgStudy

science

Model 302 telephone

Model 302 telephone is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Model 302 telephone rather than just read about it. In short: The model 302 telephone is a desk set telephone that was manufactured in the United States by Western Electric from 1937 until 1955, and by Northern Electric in Canada until the late 1950s, until well after the introduction of the 500-type telephone in 1949. The sets were routinely refurbished into the 1960s.

Model 302 telephone — main illustration
Model 302 telephone — illustration

Key takeaways

  • Model 302 telephone belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Model 302 telephone to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Model 302 telephone from memory before moving on to harder problems.

Reference excerpt

The model 302 telephone is a desk set telephone that was manufactured in the United States by Western Electric from 1937 until 1955, and by Northern Electric in Canada until the late 1950s, until well after the introduction of the 500-type telephone in 1949. The sets were routinely refurbished into the 1960s. It was one of the most widely used American combined telephone sets to include the ringer and network circuitry in the same telephone housing.

Design and production The design of a new desk telephone for the Bell System began approximately in 1930, only a short time after the introduction of a line of handset telephones, the 102 and 202-type desk telephones. The existing Western Electric telephones comprised a desk set that only served to secure the handset and also the dial for customer-initiated calling, but required an external subscriber set (subset, or desk set box or ringer box), containing the ringer and network circuitry. This box was typically mounted on a wall or desk side. New concepts of design and economic efficiency emerged in Europe, as well as in the independent market in the US, in the 1920s, which combined all components of the telephone in one desk-top unit. The model 302 was the first Western Electric telephone to follow this trend. Designed by Bell Telephone Laboratories engineer George Lum starting in the early 1930s, the 302-type telephone included such design elements of contemporary technology as, for example, in the Ericsson model DBH 1001 of 1931, conceived in 1929 by the Norwegian artist and designer Jean Heiberg, and the Automatic Electric Type 34 Monophone desk telephone, introduced in 1934.

The design evolved during the early part of the 1930s when the Great Depression delayed introduction of all new telephones. After field trials in 1936, large-scale deployment commenced in 1937. The model was never completely retired from service in the Bell System, which ceased to exist in 1984. The model 302, and a series of similar models for special service types, is designed around a rectangular steel base-plate on which are mounted the ringer unit, the induction coil, a metal container enclosing two capacitors, and a connector terminal plate. The base was supported by four felt- or leather-covered triangular feet attached under each corner to prevent scratching furniture surfaces. The housing sat atop the base, secured with screws, and contained the rotary dial and a handset cradle. The cradle contained two plungers rods which activated the hook switch mounted inside the housing, when the handset was lifted from the cradle. The majority of 302-series telephones were produced in black, with painted color sets available by 1939 at a surcharge payable by the subscriber. The housing was originally cast from a zinc alloy until production sets were increasingly made from a thermoplastic material, Tenite, by 1941. The thermoplastic housings were available in five colors: ivory, Pekin red, green, blue, and rose pink until telephone production was suspended due to the military material requirements for WW-II by orders of the War Production Board. Post-war telephone production resumed with black plastic housings in 1945 and by 1949 color sets were reintroduced. Requests for custom colors could also be fulfilled, including the traditional dark gold, statuary bronze, old brass, and oxidized silver hues. All early telephone sets had dials with metal finger wheels, either black or in brushed stainless steel for the color telephones. Starting in 1941, the colored thermoplastic units featured clear plastic finger wheels. Dial number plates were made with a steel substrate for the white vitreous enamel face. Black telephone sets were equipped from the factory with straight brown textile-covered cords until 1952, when synthetic rubber (Neoprene) jacketed cords became standard equipment. Optional retractile coiled cords were available both in textile and rubber jackets since the early 1940s. The 302 was a rugged and easily repaired desk telephone. Most US telephones were leased to subscribers from the Bell System as part of the monthly service fees. Western Electric also built 302 telephones for sale to independent telephone companies.

Beginning in August 1955 and extending into the 1960s, the Bell System remanufactured the 302 as the type 5302 in its distribution center work shops, with a newly designed housing and eventually with the G-type handset of the 500-type telephone, which gave the set a similar appearance to the 500. In addition to the model 302, the Western Electric 300-series included many variations and special purpose types with additional features. Conversion kits using a 302-style housing and F1 handset to replace older manual candlestick telephones with an external subset were available.

Similar phones by other manufacturers

Other manufacturers produced sets of similar appearance. Among these were the Stromberg-Carlson Model 1243 telephone, distinguished by beveled corners and flanging on the handset, and the Federal Telephone & Radio (FTR) 803 (pictured). After phase-out in the US, the model 302's exterior design was retained by European Bell branch companies for such models as the 1954 Bell Standard, widely used in the Netherlands and Belgium.

See also Western Electric hand telephone sets

References

External links Western Electric Telephone Models Western Electric 300-series Models

Illustrations

Model 302 telephone: Western Electric 302 telephone with a thermoplastic case
Western Electric 302 telephone with a thermoplastic case
Model 302 telephone: The Ericsson model DBH 1001 of 1931 may have been an influence on the later Model 302 design.
The Ericsson model DBH 1001 of 1931 may have been an influence on the later Model 302 design.
Model 302 telephone: 1948 Western Electric 302 telephone set that was refurbished amidst post-war equipment shortages with an older style handset (E1) and installed on a line of the Newark, NJ, exchange "BIgelow", the last existing Panel office when it was dismantled in 1983.
1948 Western Electric 302 telephone set that was refurbished amidst post-war equipment shortages with an older style handset (E1) and installed on a line of the Newark, NJ, exchange "BIgelow", the last existing Panel office when it was dismantled in 1983.
Model 302 telephone: A 1945 Federal Telephone & Radio Type 803, a clone of the 302 using Automatic Electric components for military applications
A 1945 Federal Telephone & Radio Type 803, a clone of the 302 using Automatic Electric components for military applications

Worked examples

Example 1 — a first encounter with Model 302 telephone

Start with the simplest possible case. Write down what Model 302 telephone claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Model 302 telephone before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Model 302 telephone ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Model 302 telephone

In research
Model 302 telephone appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Model 302 telephone in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Model 302 telephone is common in secondary-school and first-year university syllabi. It links to neighbouring topics Telephony equipment, Western Electric telephones, so understanding it makes those chapters shorter.
In everyday life
Look for Model 302 telephone outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Model 302 telephone” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Model 302 telephone in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Model 302 telephone means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Model 302 telephone out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Model 302 telephone in simple terms?

The model 302 telephone is a desk set telephone that was manufactured in the United States by Western Electric from 1937 until 1955, and by Northern Electric in Canada until the late 1950s, until well after the introduction of the 500-type telephone in 1949. The sets were routinely refurbished into…

Why does Model 302 telephone matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Model 302 telephone?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Model 302 telephone.

Tags

  • Telephony equipment
  • Western Electric telephones

Keep exploring