Communications

What antenna polarization is used with public safety service equipment and FM broadcast?

A class-C RF amplifier is collector amplitude modulated and its average dc level collector current does not change. This means

Normally, a linear class B RF power amplifier operates with a bias approximately equal to

The purpose why an RF amplifier is operated under linear class-B conditions (as opposed to class-C) is to

The type of emission that suffer most from selective fading.

A receiver selectivity of 10 kHz in the IF circuitry is optimum for what type of signals?

How is a G3E FM-phone signals produced?

A way of eliminating auto interference to radio reception

Cross-modulation in a receiver can be reduced by

What is the cause of receiver desensitizing?

An RF stage precedes the mixer stage in a superhet receiver. One advantage of including this RF stage is

What is an undesirable effect of using a too-wide filter bandwidth in the IF section of a receiver?

A system containing a limiter stage, a discriminator, and a de-emphasis circuit?

The limiter stage of an FM receiver

High selectivity occurs when the degree of coupling between a receiver's RF stages is

A carrier is phase modulated by a test tone. If the amplitude and the frequency of the tone are both doubled, the amount of the deviation is

The base in an RF amplifier is grounded in order to

The AM detector performs two basic functions in the receiver.

A varactor diode can be used in a/an

Receiver interference is not reduced by including a/an