science

SCR-189

SCR-189 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-189 rather than just read about it. In short: The SCR-189 was a mobile Signal Corps Radio tested by the United States Army before World War II. It was designed for armored forces, and mounted in the Six Ton Tank M1917.

Key takeaways

SCR-189 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-189 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of SCR-189 from memory before moving on to harder problems.

Reference excerpt

The SCR-189 was a mobile Signal Corps Radio tested by the United States Army before World War II. It was designed for armored forces, and mounted in the Six Ton Tank M1917. The original production run of these tanks included 50 "radio tanks" but the original radio components are unknown, so what or how many tanks were fitted with the SCR-189 also appears to be unknown.

Use

An early tactical vehicle radio, it was the first Army set to utilize the Superheterodyne receiver. As the M1917 tank was phased out, the new M1 Combat Car and M2 Light Tank were equipped with SCR-189's. The SCR-189 was replaced by the SCR-245 in 1937.

Components BC-175 Receiver BC-176 Transmitter CW/voice, 2.2 to 2.6 kHz (136.27 to 115.30 km) at 7.5 watts, range 8 miles (13 km) BC-177 Control box BC-206 Control box PE-48 Power supply Battery box BX-3 (Battery BA-27)

Variants SCR-190 Receiver only set

See also Radio Tractor Signal Corps Radio SCR-193 Crystal radio

References

External links https://web.archive.org/web/20100413132056/http://www.gordon.army.mil/ocos/museum/equipment.asp scr and bc lists

Illustrations

Worked examples

Example 1 — a first encounter with SCR-189

Start with the simplest possible case. Write down what SCR-189 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-189 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-189 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-189

In research: SCR-189 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-189 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-189 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Amateur radio transmitters, Military electronics of the United States, Military equipment introduced in the 1930s, so understanding it makes those chapters shorter.
In everyday life: Look for SCR-189 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-189 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what SCR-189 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-189 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is SCR-189 in simple terms?

The SCR-189 was a mobile Signal Corps Radio tested by the United States Army before World War II. It was designed for armored forces, and mounted in the Six Ton Tank M1917.

Why does SCR-189 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-189?

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-189.