8-33D: Variable Range Markers

Question 1

8-33D1

The variable range marker signal is normally fed to the input of the:

A. Sweep amplifier.
B. Low voltage power supply regulator.
C. Video amplifier.
D. Range ring oscillator.

Answer 1

ANSWER C
The variable range marker is an important display feature. It allows the operator to calculate the distance to a target. Non-variable range marks are equally spaced, and are produced only for the duration of the range marker gate pulse. The variable range marker signal is an additional range ring, fed to the input of the video amplifier, and ultimately displayed on the RADAR indicator.

Question 2

8-33D5

An important component of the VRM system is the:

A. Resolver.
B. Interference rejection circuit.
C. STC sensitivity control.
D. Shift register.

Answer 2

ANSWER D
The variagle range marker system is fed timing triggers by a master oscillator, and then fed to dividing circuits, usually consisting of flip-flops, where pulses may be variable divided to longer range readouts. The shift register faithfully tracks any changes dialed-in by the operator adjusting the variable range marker.

Question 3

8-33D6

Which of the following statements about the Variable Range Marker system is correct?

A. The VRM is an auxiliary output of the fixed range marker oscillator.
B. The VRM system develops a single adjustable range ring.
C. The VRM system is calibrated using a frequency counter.
D. The VRM system is controlled by a crystal oscillator.

Answer 3

ANSWER B
A variable range marker indicator is usually a single adjustable range ring.