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Element 8: Ship Radar Techniques

effective 6/25/2009

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8-C-21: Local Oscillators

8-21C1: The error voltage from the discriminator is applied to the:

Repeller (reflector) of the klystron.

Grids of the IF amplifier.

Grids of the RF amplifiers.

Magnetron.



8-21C2: In a RADAR unit, the local oscillator is a:

Klystron.

Hydrogen Thyratron.

Pentagrid converter tube.

Reactance tube modulator.



Figure 8A1

8-21C3: What component of a RADAR receiver is represented by block 48 in Fig. 8A1?

Klystron (local oscillator).

Discriminator.

IF amplifier.

Crystal detector.



8-21C4: What device(s) could be used as the local oscillator in a RADAR receiver?

Klystron and a Gunn Diode

Thyratron

Klystron

Gunn diode



8-21C5: The klystron local oscillator is constantly kept on frequency by:

The Automatic Frequency Control circuit.

Constant manual adjustments.

A feedback loop from the crystal detector.

A feedback loop from the TR box.



8-21C6: How may the frequency of the klystron be varied?

Small changes can be made by adjusting the repeller voltage and large changes can be made by adjusting the size of the resonant cavity.

Small changes can be made by adjusting the anode voltage.

Large changes can be made by adjusting the frequency.

By changing the phasing of the buncher grids





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Element 8: Ship Radar Techniques
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