Technician Licensing Class Multi-Mode Radio Excitement Section 6 Valid July 1, 2014 Through June 30,...

Technician Licensing Class

Multi-Mode Radio Excitement

Section 6

Valid July 1, 2014

Through

June 30, 2018


• T7A02 A “transceiver” combines both transmitting and receiving functions in one package

• T7A09 A multi-mode VHF transceiver is most useful for VHF weak-signal communication.


T7A08 Modulation is the process of applying information (voice, video, or digital) onto a radio signal

4



T8A01 Single sideband is a form of amplitude modulation.

Carrier only CW Tones produce both side bands

or AM

Remove one sideband and

suppress carrier becomes SSB

• T8A03 Single Sideband (SSB) is the type of voice mode is most often used for long-distance (weak signal) contacts on the VHF and UHF bands.


• T8A07 The primary advantage of single sideband over FM for voice transmissions is that SSB signals have narrower bandwidth

• T8A08 3 kHz is the approximate bandwidth of a single sideband voice signal.

• T4B09 For single sideband -- 2400 Hz would be the appropriate receive filter to minimize noise and interference

• T8A06 The upper sideband is normally used for 10 meter HF, VHF and UHF single-sideband communications


• T2B13 The use of SSB phone is permitted in at least some portion of all the amateur bands above 50 MHz

•T4B06 The receiver RIT or clarifier controls could be used if the

voice pitch of a single-sideband signal seems too high or low.

•T4B7 The term "RIT" means Receiver Incremental Tuning.Set knob to neutral, press RIT button to turn on function, and then adjust

slightly for proper SSB voice reception

RIT adjusts voice pitch, not the frequency of received station.


• T4A1 Some microphone connectors on amateur transceivers include push-to-talk functions and voltage links for powering the microphone.

• T7A05 An oscillator is a circuit that generates a signal of a desired frequency.


• T8A05 CW (Continuous Wave or Morse Code) is the type of emission that has the narrowest bandwidth.

• T8A11 150 Hz is the approximate maximum bandwidth required to transmit a CW signal.

CW Signal 150 Hz wide

SSB Signal 2 - 3 kHz wide

FM Signal 5 - 15 kHz wide

UHF Fast-Scan TV ~ 6 MHz


• T4B10 500 Hz is an appropriate receive filter to select in order to minimize noise and interference for CW reception.

• Bandwidth filters vary for the mode being received.

• T4B08 The advantage of having multiple receive bandwidth choices on a multimode transceiver will permit noise or interference reduction by selecting a bandwidth matching the mode.


• T7A03 The function of a mixer is to convert a radio signal from one frequency to another.

MIXER(In AM Broadcast

Receiver)

Intermediate Frequency

Station Signal

Signal C at 455 kHz

Signal B at 1255 kHz (or at 1655 kHz)

Local Oscillator

Signal A at 800 kHz (or at

1200 kHz)

Block Diagram of an AM Broadcast Receiver Mixer


• T7A04 Selectivity is the term that describes the ability of a receiver to discriminate between multiple signals.

• T7A01 Sensitivity is the ability of a receiver to detect the presence of a signal.

• T4B12 AGC or automatic gain control is used to keep received audio relatively constant.

• T7A11 An RF pre-amp is installed between the antenna input and the receiver.

Multi-Mode Excitement

• T7A06 A transverter is a device that takes the output of a low-powered 28 MHz SSB exciter and produces a 222 MHz output signal.

Your First Radio

T4A03 Preventing voltage fluctuations from reaching sensitive circuits is a good reason to use a regulated power supply for communications equipment.

Jetstream JTPS30M Regulated Power Supply

MFJ-4125 13.8VDC@22Amp

Take Aways

Take Aways

A “transceiver” combines both transmitting and receiving functions in one package

A multi-mode VHF transceiver is most useful for VHF weak‑signal communication.

Modulation is the process of applying information (voice, video, or digital) onto a radio signal

Single sideband is a form of amplitude modulation

Single Sideband (SSB) is the type of voice mode is most often used for long-distance (weak signal) contacts on the VHF and UHF bands.

Take Aways

The primary advantage of single sideband over FM for voice transmissions is that SSB signals have narrower bandwidth

3 kHz is the approximate bandwidth of a single sideband voice signal. (3 kHz equals 3000 Hz)

For single sideband 2400 Hz would be the appropriate receive filter to minimize noise and interference

The upper sideband is normally used for 10 meter HF, all VHF and all UHF single-sideband communications

Take Aways

The use of SSB phone is permitted in at least some portion of all the amateur bands above 50 MHz

The receiver RIT or clarifier controls could be used if the voice pitch of a single-sideband signal seems too high or low.

The term "RIT" means Receiver Incremental Tuning.

• Some microphone connectors on amateur transceivers include push-to-talk functions and voltage links for powering the microphone.

• An oscillator is a circuit that generates a signal of a desired frequency.

Take Aways

In comparison to SSB and FM, CW emission has the narrowest bandwidth.

The approximate maximum bandwidth to transmit a CW signal is 150 Hz

An appropriate receive filter used in order to minimize noise and interference for CW reception is 500 Hz.

The advantage of having multiple receive bandwidth choices on a multimode transceiver permits noise or interference reduction by selecting a bandwidth matching the mode.

Take Aways

The function of a mixer is to convert a radio signal from one frequency to another

Selectivity is the term that describes the ability of a receiver to discriminate between multiple signals.

Sensitivity is the ability of a receiver to detect the resence of a signal.

AGC or automatic gain control is used to keep received audio relatively constant.

An RF pre-amp is installed between the antenna input and the receiver.

Take Aways

A transverter is a device that takes the output of a low-powered 28 MHz SSB exciter and produces a 222 MHz output signal.

Preventing voltage fluctuations from reaching sensitive circuits is a good reason to use a regulated power supply for communications equipment.

Valid July 1, 2014

Through

June 30, 2018

Multi-ModeRadio

Excitement

Element 2 Technician Class Question Pool

Element 2 Technician Class Question Pool

23

T7A02 What is a transceiver?

A. A type of antenna switch B. A unit combining the functions of a

transmitter and receiverC. A component in a repeater which filters

out unwanted interferenceD. A type of antenna matching network

24

T7A09 Which of the following devices is most useful for VHF weak-signal communication?

A. A quarter-wave vertical antenna

B. A multi-mode VHF transceiver

C. An omni-directional antenna

D. A mobile VHF FM transceiver

25

T8A03 Which type of voice mode is most often used for long-distance (weak signal) contacts on the VHF and UHF bands ?

A. FM

B. DRM

C. SSB

D. PM

26

T8A07 What is the primary advantage of single sideband over FM for voice transmissions?

A. SSB signals are easier to tune

B. SSB signals are less susceptible to interference

C. SSB signals have narrower bandwidth

D. All of these choices are correct

27

T8A01 Which of the following is a form of amplitude modulation?

A. Spread-spectrum

B. Packet radio

C. Single sideband

D. Phase shift keying

28

T8A06 Which sideband is normally used for 10 meter HF, VHF and UHF single-sideband

communications?

A. Upper sideband

B. Lower sideband

C. Suppressed sideband

D. Inverted sideband

29

T7A08 Which of the following describescombining speech with an RF carrier signal?

A. Impedance matching

B. Oscillation

C. Modulation

D. Low-pass filtering

30

T8A08 What is the approximate bandwidth of a single sideband voice signal?

A. 1 kHz

B. 3 kHz

C. 6 kHz

D. 15 kHz

31

T4B09 Which of the following is an appropriate receive filter bandwidth to select in order to minimize noise and interference for SSB reception?

A. 500 Hz

B. 1000 Hz

C. 2400 Hz

D. 5000 Hz

32

T2B13 Which of the following is true of the use of SSB phone in amateur bands above 50 MHz?

A. It is permitted only by holders of a General Class or higher license

B. It is permitted only on repeaters

C. It is permitted in at least some portion of all the amateur bands above 50 MHz

D. It is permitted only on when power is limited to no more than 100 watts

33

T4B06 Which of the following controls could be used if the voice pitch of a single-sideband signal seems too high or low?

A. The AGC or limiter

B. The bandwidth selection

C. The tone squelch

D. The receiver RIT or clarifier

34

T4B07 What does the term "RIT" mean?

A. Receiver Input Tone

B. Receiver Incremental Tuning

C. Rectifier Inverter Test

D. Remote Input Transmitter

35

T4A01 Which of the following is true concerning the microphone connectors on amateur transceivers?

A. All transceivers use the same microphone connector type

B. Some connectors include push-to-talk and voltages for powering the microphone

C. All transceivers using the same connector type are wired identically

D. Un-keyed connectors allow any microphone to be connected

36

T7A05 What is the name of a circuit that generates a signal of a desired frequency?

A. Reactance modulator

B. Product detector

C. Low-pass filter

D. Oscillator

37

T8A05 Which of the following types of emission has the narrowest bandwidth?

A. FM voice

B. SSB voice

C. CW

D. Slow-scan TV

38

T8A11 What is the approximate maximum bandwidth required to transmit a CW signal?

A. 2.4 kHz

B. 150 Hz

C. 1000 Hz

D. 15 kHz

39

T4B10 Which of the following is an appropriate receive filter bandwidth to select in order to minimize noise and interference for CW reception?

A. 500 Hz

B. 1000 Hz

C. 2400 Hz

D. 5000 Hz

40

T4B08 What is the advantage of having multiple receive bandwidth choices on a multimode transceiver?

A. Permits monitoring several modes at once

B. Permits noise or interference reduction by selecting a bandwidth matching the mode

C. Increases the number of frequencies that can be stored in memory

D. Increases the amount of offset between receive and transmit frequencies

41

T7A01 Which term describes the ability of a receiver to detect the presence of a signal?

A. Linearity

B. Sensitivity

C. Selectivity

D. Total Harmonic Distortion

42

T7A03 Which of the following is used to convert a radio signal from one frequency to another?

A. Phase splitter

B. Mixer

C. Inverter

D. Amplifier

43

T7A04 Which term describes the ability of a receiver to discriminate between multiple signals?

A. Discrimination ratio

B. Sensitivity

C. Selectivity

D. Harmonic Distortion

44

T4B12 What is the function of automatic gain control or AGC?

A. To keep received audio relatively constant

B. To protect an antenna from lightning

C. To eliminate RF on the station cabling

D. asymmetric goniometer control used for antenna matching

45

T7A11 Where is an RF preamplifier installed?

A. Between the antenna and the receiver

B. At the output of the transmitter’s power amplifier

C. Between transmitter and antenna tuner

D. At the receiver’s audio output

46

T7A06 What device takes the output of a low-powered 28 MHz SSB exciter and produces a 222 MHz output signal?

A. High-pass filter

B. Low-pass filter

C. Transverter

D. Phase converter

47

T4A03 Which is a good reason to use a regulated power supply for communications equipment?

A. It prevents voltage fluctuations from reaching sensitive circuits

B. A regulated power supply has FCC approval

C. A fuse or circuit breaker regulates the power

D. Power consumption is independent of load

Technician Licensing Class Multi-Mode Radio Excitement Section 6 Valid July 1, 2014 Through June 30,...

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