Questions - H F Station Arrangements
Question file 15
STUDY NOTES
QUESTIONS
WITH ANSWERS
- In the block diagram shown, the "linear amplifier" is:
- an amplifier to remove distortion in signals from the transceiver
- an optional amplifier to be switched in when higher power is required
- an amplifier with all components arranged in-line
- a push-pull amplifier to cancel second harmonic distortion
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- In the block diagram shown, the additional signal path above the
"linear amplifier" block indicates that:
- some power is passed around the linear amplifier for stability
- "feed-forward" correction is being used to increase
linearity
- the linear amplifier input and output terminals may be short-circuited
- the linear amplifier may be optionally switched out of circuit to
reduce output power
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- In the block diagram shown, the "low pass filter" must be rated
to:
- carry the full power output from the station
- filter out higher-frequency modulation components for maximum
intelligibility
- filter out high-amplitude sideband components
- emphasise low-speed Morse code output
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- In the block diagram shown, the "SWR bridge" is a:
- switched wave rectifier for monitoring power output
- static wave reducer to minimize static electricity from the antenna
- device to monitor the standing-wave-ratio on the antenna feedline
- short wave rectifier to protect against lightning strikes
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- In the block diagram shown, the "antenna switch":
- switches the transmitter output to the dummy load for tune-up purposes
- switches the antenna from transmit to receive
- switches the frequency of the antenna for operation on different bands
- switches surplus output power from the antenna to the dummy load to
avoid distortion.
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- In the block diagram shown, the "antenna tuner":
- adjusts the resonant frequency of the antenna to minimize harmonic
radiation
- adjusts the resonant frequency of the antenna to maximise power output
- changes the standing-wave-ratio on the transmission line to the
antenna
- adjusts the impedance of the antenna system seen at the transceiver
output
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- In the block diagram shown, the "dummy load" is:
- used to allow adjustment of the transmitter without causing
interference to others
- a load used to absorb surplus power which is rejected by the antenna
system
- used to absorb high-voltage impulses caused by lightning strikes to
the antenna
- an additional load used to compensate for a badly-tuned antenna system
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- In the block diagram shown, the connection between the SWR bridge and the
antenna switch is normally a:
- twisted pair cable
- coaxial cable
- quarter-wave matching section
- short length of balanced ladder-line
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- In this block diagram, the block designated "antenna tuner" is
not normally necessary when:
- the antenna input impedance is 50 ohms
- a half wave antenna is used, fed at one end
- the antenna is very long compared to a wavelength
- the antenna is very short compared to a wavelength
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- In the block diagram shown, the connection between the "antenna
tuner" and the "antenna" could be made with:
- three-wire mains power cable
- heavy hook-up wire
- 50 ohm coaxial cable
- an iron-cored transformer
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