7-A-012: Antennas
7-12B1:
A vertical (whip) antenna has a radiation pattern best described by?
A circle
A figure eight
A cardiod
An ellipse
7-12B2:
Why is an antenna tuner required for MF-HF transmissions?
The length of physically-fixed antenna must be electrically matched to the intended frequency of operation.
The longer antenna tuner calculates the proper spectrum band for the operator to use.
To ensure transmissions are restricted to legal marine frequencies.
The antenna tuner indicates whether the ionosphere is ready to reflect a transmission properly.
7-12B3:
A vertical quarter wave antenna with a good ground connection will:
Radiate omni-directionally.
Radiate directionally due to being grounded.
Not function due to being grounded.
Only be used in Satellite communications.
7-12B4:
What is the most common type of antenna for GMDSS MF-HF?
Vertically polarized whip antenna
Horizontally polarized long wire antenna.
Horizontally polarized vertical whip antenna.
Satellite radome with vertical polarization.
7-12B5:
What is the purpose or function of the antenna coupler?
All of these answers are functions of the antenna coupler.
Electrically matching the antenna system to the transmit frequency.
Changing the overall wavelength of the antenna system (in addition to the fixed length whip.)
Enabling maximum transmitted signal on the band chosen by the operator.
7-12B6:
What advantage does a vertical whip have over a long wire?
It radiates equally well in all directions.
It radiates directionally for better propagation.
It radiates a strong signal vertically.
It radiates more signal fore and aft.
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