science

SCR-299

SCR-299 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 SCR-299 rather than just read about it. In short: The SCR-299 was a U.S. Signal Corps mobile military communications unit used during World War II.

Key takeaways

SCR-299 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect SCR-299 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of SCR-299 from memory before moving on to harder problems.

Reference excerpt

The SCR-299 was a U.S. Signal Corps mobile military communications unit used during World War II.

History

The SCR-299 "mobile communications unit" was developed to provide long-range communications during World War II. The US Military sought improvements of range, flexibility and durability over its existing SCR-197 and SCR-597 transmitters. In 1942, Hallicrafters Standard HT-4 was selected as the SCR-299's transmitter, known subsequently by its military designation as the BC-610. The SCR-299 was first used on 8 November 1942 during Operation TORCH involving companies of the 829th Signal Service Battalion establishing a radio net that could exchange messages between beach-landed forces and bases in Gibraltar. Despite initial problems unloading the sets from convoy ships, the SCR-299s served until the installation of permanent Army Command and Administrative Network stations. According to US Army military historians, "General Dwight Eisenhower credited the SCR-299 in his successful reorganization of the American forces and final defeat of the Nazis at Kasserine Pass."

The range of the SCR-299 exceeded original specifications, sometime establishing contact over 2,300 miles (3,700 km). The SCR-299 provided reliable communications with England during the North African campaign, and in Normandy on D-Day, served as a connection between two airborne divisions with Britain. The SCR-299 was also used in the invasion of Sicily and the Allied invasion of Italy. War correspondents and press reporters frequently made use of the SCR-299 and SCR-399. Access to the sets was provided to them by US Second Army and US Third Army Group Communications Teams, and in one instance, the SCR-399 became the only means of getting press copy direct to London. In 1944, a short subject film was produced by the Jam Handy Organization and sponsored by the Hallicrafters Company that showed the construction of the SCR-299 and dramatized its use during World War II. Hallicrafters Company advertising of the period sometimes used illustrations of the shelter-mounted SCR-399 to describe the achievements of the SCR-299.

Specifications

Transmitter: BC-610 plus BC-614 (speech amplifier), BC-729 (tuning unit) and BC-211 (frequency meter) Transmitter output power: 350 watts. Receivers: BC-312 and BC-342 Frequency coverage: HF from 2 to 8 MHz (and 1–18 MHz using conversion kits) Power supply: 2000 watts, with additional 1500 watts for heater and lights supplied by PE-95 (power unit) on K-52 "Ben-Hur" style trailer. Optional 12 volt storage battery, or 115 volt 60 cycle AC commercial power and two spare 6 volt storage batteries SCR-299 housing: K-51 van truck SCR-399 housing: HO-17 shelter mountable on 21⁄2-ton trucks. SCR-499 housing: air-transportable Frequency Conversion Kit MC-503: coverage down to 1 MHz. Frequency Conversion Kit MC-516: coverage to 12 MHz Frequency Conversion Kit MC-517: coverage to 18 MHz. Antennas: 9-foot (2.7 m) whip antenna (receiver), 15-foot (4.6 m) whip antenna (transmitter). Optional 21 ft (6.4 m) whip antenna while stationary or 45 ft (14 m) auxiliary wire antenna for 2.0 to 4.5 MHz coverage. Remote control: field telephones, control boxes and cable.

See also ARC-5 BC-348 BC-654 BC-610 Collins Radio Hallicrafters SX-28 M-209 R-390A SCR-300 SCR-536 Signal Corps Radio Wireless Set No. 19 List of U.S. Signal Corps Vehicles

Notes

References TM 11-227, 10 April 1944 TM 11-280-B TM 11-487 Oct. 1944, page 406

External links Hallicrafters HT-4, to War and home again The SCR299, Army Communicator United States Army Signal Center, Fort Gordon, GA SCR and BC list US Army training film featuring K-55 trailer and SCR-299 Directory of Communications Electronic Equipment BC-610 data sheet Voice of victory

Illustrations

Worked examples

Example 1 — a first encounter with SCR-299

Start with the simplest possible case. Write down what SCR-299 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 SCR-299 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 SCR-299 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 SCR-299

In research: SCR-299 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 SCR-299 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: SCR-299 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Military electronics of the United States, Military equipment introduced from 1940 to 1944, Military radio systems of the United States, so understanding it makes those chapters shorter.
In everyday life: Look for SCR-299 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.

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How to study SCR-299 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what SCR-299 means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain SCR-299 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is SCR-299 in simple terms?

The SCR-299 was a U.S. Signal Corps mobile military communications unit used during World War II.

Why does SCR-299 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 SCR-299?

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 SCR-299.