SS0002 Practice Exercise 1 Answer Key And Feedback
Introduction to Tactical Radio Communications Theory
| 1. |
Which of the following types of waves is most likely to be affected by sunspots?
|
A. Sky-waves.
Since sky-waves propagate by reflecting off the ionosphere, any disturbance in the ionosphere can cause a disturbance in a sky-wave transmission. The 11-year regular variations in the ionosphere are caused by sunspots, and these variations will affect sky-wave transmission. Since the other types of waves are not affected by the ionosphere, they should not be affected by sunspots.
|
|
|
| 2. |
Which of the following statements about AM/SSB radios is NOT true?
|
B. AM/SSB systems are larger and heavier than AM/DSB systems.
In fact, one advantage of AM/SSB systems is that, because they electronically suppress one sideband and the Carrier, less energy is required for the same power transmission. This means that power supplies do not have to be as large, making the overall radio smaller and lighter than a comparable AM/DSB system.
|
|
|
| 3. |
You are constructing a long-wire antenna three wavelengths long to communicate on a channel frequency of 29.274 MHz. How long should you make your antenna?
|
C. 100.0 feet.
Three wavelengths is six half-wavelengths. Using the formula for long-wire antennas gives:
|
|
|
| 4. |
You are in the field and one of your antenna insulators has broken. Which of the following items will make the best replacement?
|
C. A plastic shirt button.
In order of preference, the items to use would be the button, then the tree branch (if it was not still green), then the shoelace. The can top or a green tree branch would not work because they would conduct too much current to the ground.
|
|
|
GO TO:
Lesson 2
Table of Contents
