MIDTERM TEST

Question 1

The impedance of an aircraft headphone set is:

Answer 1

500-600ohms

Question 2

The standard audio test frequency is?

Answer 2

1kHz

Question 3

The audio bandwidth for aircraft systems is?

Answer 3

350Hz to 2.5kHz

Question 4

What is the impedance of an aircraft system microphone?

Answer 4

150ohms

Question 5

Where does the required microphone bias voltage come from?

Answer 5

The radio in use

Question 6

What output voltage would you expect to have from an aircraft microphone?

Answer 6

1Vrms

Question 7

The ring of the shown Jack is for?

Answer 7

Microphone Audio

Question 8

If an amplifier has a gain of 60dB and input voltage is 1mV what is the output voltage?

Answer 8

1V

Question 9

A transmitter has 3 stages with gains of 6dB, 12dB, and 8dB (total 26dB) if 60mW is input power what is the output power?

Answer 9

24W

Question 10

If a signal generator attenuator is set to minus 30dBm what output power is sent?

Answer 10

1microWatt

Question 11

When testing a 121.5MHz ELT what time restriction must be observed?

Answer 11

First 5min after the hour

Question 12

ELTs have an arrow on the case. For proper installation where should the arrow point?

Answer 12

Towards the direction of flight / front of aircraft

Question 13

What advantage does the 406MHz ELT have over 121.5MHz ELT?

Answer 13

Gives more accurate position coordinates

Question 14

ELT batteries must be replaced after activation of the ELT for a period of?

Answer 14

Unknown duration

Question 15

Replacement of ELT batteries should be done?

Answer 15

When testing shows insufficient charge

Question 16

When carrying out a VSWR test a forward power of 100W and reverse power of 1 watt is measured, what is the VSWR?

Answer 16

1.2:1

Question 17

What value of VSWR is the acceptable limit(100W to 10W)?

Answer 17

2:1

Question 18

If the antenna transmission line (co-ax) is open circuit what VSWR or SWR would be measured?

Answer 18

5:1

Question 19

When testing a transmission line with a TDR, what indication would a short in the line show as?

Answer 19

Downward deflection on trace

Question 20

The communication receiver squelch circuit uses _____ to operate the switch/gate?

Answer 20

Internal receiver noise

Question 21

An ELT has to be inspected every?

Answer 21

1 year

Question 22

What is the transmits power output used on the 406MHz ELT?

Answer 22

5Watts

Question 23

Ground stations are identified during radios communications by?

Answer 23

Airport name and station type, ie Toronto tower.

Question 24

What is the spoken word for distress?

Answer 24

Mayday

Question 25

The 406 MHz ELT output consists of a ______ but pulse train

Answer 25

112

Question 26

What does the term selectivity of a radio receiver refer to?

Answer 26

It’s ability to choose only the desired frequency

Question 27

What is the image frequency of a radio receiver if the local oscillator is 111.2MHz and the radio is tuned to receive 121.9MHz

Answer 27

100.5MHz

Question 28

The 406 ELT transmits for ______ every _______

Answer 28

0.5s every 50s

Question 29

The 406MHz ELT output is a digital format that uses ______ modulation

Answer 29

Phase/DPSK

Question 30

According to the radiotelephone operators guide Coordinated Universal time (UTC) is used to avoid confusion between different time zones. What is the accepted abbreviation for UTC?

Answer 30

Zulu time