Block 4 - 1I - Receivers and Transmitters

What is the main purpose of radios in aircrafts?

• To communicate with ground and other air crafts

• To communicate with gnomes

• To communicate with speakers and headphones

• To communicate with animals

What is the purpose of receivers and transmitters?

• To modulate the transmitted signal and demodulate the received signal

• To modulate the USB and demodulate the LSB

• To modulate the RF transmitter and demodulate intelligence signals

• To regulate the voltage RF transmitters are receiving

In our work book, basic comm systems have how many components?

• 7

• 6

• 8

• 12

Answer explanation

Most cmm systems will have the control unit, receiver, synthesizers, transmitter, power, antenna, and headset

What is the purpose of the control unit?

• To act as an interface between the operator and their comm system

• To act as an interference between the operator and the R/T

• To act as an interface between the operator and the R/T

The purpose of the synthesizer is…

• To provide the carrier frequency for the transmitter section and the injection frequency for the control unit

• To generate stable and precise frequencies for use by both the receiver and transmitter sections

• To allow the R/T to transmit intelligence on or around the selected frequency

• To create the injection frequency to be used in the receiver section to create and IF Frequenycy in the receiver section

The Transmitter section does what?

• Modulates the carrier frequency from the flight crew’s microphone and transmits it out the antenna

• Uses the flight crew’s microphone to create a shock wave to shut off the enemy antenna

• Modulates the carrier frequency to create a thunder storm

• Modulated the carrier frequency from the flight crew’s microphone and transmits it out the reciever

Selectivity is…

• The ability to select one frequency among many closely spaces frequencies

• The ability to remove undesirable amplitude deviations of the signal

• The ability to provide gain to incoming signals from the demodulator

• The ability to provide gain to the to the incoming IF from the RF mixer

Sensitivity is..

• The measure of a receiver’s ability to pick up very weak signals

• The ability to amplify very small AC voltages received by the antenna for use by other stages in the reciever

• The ability to heterodyne the receiver RF signal with the injection frequency from the synthesizer to produce a lower frequency

• The ability to attach the intelligence to the transmitted signal

• The ability to extract the intelligence from the transmitted signal

Which component is described as a “Lawn Mower?”

• The RF Amplifier

• The Peak Limiter

• The Audio Amplifier

• The Synthesizer

Which component produces four frequencies?

• The RF Mixer

• The IF Amplifier

• The Demodulator

• The Audio Amplifier

Answer explanation

Similar to our previous chapter, the RF Mixer produces four frequencies; the two originals, the sum, and the difference.