NZART Amateur Examination &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp &nbsp page 7&nbsp &nbsp &nbsp &nbsp &nbsp NZARTX07 Security code 267036
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<br>

<li>  The purpose of the final amplifier in a transmitter is to: 

<ol type = a>

<li> increase the frequency of a signal 

<li> isolate the multiplier and later stages 

<li> produce a stable radio frequency 

<li> increase the power fed to the antenna 


</ol>
<br>

<li>  Harmonics are produced when: 

<ol type = a>

<li> a resonant circuit is detuned 

<li> negative feedback is applied to an amplifier 

<li> a transistor is biased for class A operation 

<li> a sine wave is distorted 


</ol>
<br>

<li>  The following is installed in the transmission line as close 
as possible to a 
HF transmitter to reduce harmonic output: 

<ol type = a>

<li> a middle-pass filter 

<li> a low-pass filter 

<li> a high-pass filter 

<li> a band-reject filter 


</ol>
<br>

<li>  The following unit in a DC power supply performs a 
rectifying operation: 

<ol type = a>

<li> an electrolytic capacitor 

<li> a fuse 

<li> a crowbar 

<li> a full-wave diode bridge 


</ol>
<br>

<li>  In a regulated power supply, 'current limiting' is 
sometimes used to: 

<ol type = a>

<li> prevent transformer core saturation 

<li> protect the mains fuse 

<li> minimise short-circuit current passing through the 
regulator 

<li> eliminate earth-leakage effects 


</ol>
<br>

<li>  The correct order for callsigns in a callsign exchange at 
the start and end of 
a transmission is: 

<ol type = a>

<li> the other callsign followed by your own callsign 

<li> your callsign followed by the other callsign 

<li> your own callsign, repeated twice 

<li> the other callsign, repeated twice 


</ol>
</ol>
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