Intro to General License Quiz
On which HF and/or MF amateur bands are there portions where General class licensees cannot transmit?
Four HF bands have segments allocated only for Amateur Extra licensees and those are 80 meters, 40 meters, 20 meters and 15 meters.
What does it mean when a U.S. station in the lower 48 states is calling “CQ DX”?
“CQ DX” is a call for distant stations, specifically outside the lower 48 states in this case.
Which of the following would reduce RF interference caused by common-mode current on an audio cable?
Ferrite chokes sometimes are referred to as ferrite beads. The choke usually will stop the flow of RF on the audio cable. This technique is also effective on other cables connected to your computer such as the USB cable and mouse cable. Placing a ferrite choke around the cable would reduce RF interference caused by common-mode current on an audio cable.
What is a dipole antenna with a single center support typically called?
The inverted V name comes from the antenna’s shape when supported at the center.
What happens to the feed-point impedance of a horizontal half-wave dipole as it is lowered toward 1/10 of a wavelength above the ground?
As a horizontal half-wave dipole is lowered closer to the ground (around 1/10 wavelength), the antenna begins to interact more strongly with the ground. The ground reflects the antenna’s signal, and this reflection is out of phase with the original signal. So the key idea: Closer to ground → more interaction and losses → lower radiation resistance → lower feed-point impedance.
