General Class

In an ARQ mode, what is meant by a NAK response to a transmitted packet?

What action results from a failure to exchange information due to excessive transmission attempts when using an ARQ mode?

Which of the following narrow-band digital modes can receive signals with very low signal-to-noise ratios?

Which of the following statements is true about PSK31?

Which is true of mesh network microwave nodes?

How does forward error correction (FEC) allow the receiver to correct data errors?

How are the two separate frequencies of a Frequency Shift Keyed (FSK) signal identified?

Which type of code is used for sending characters in a PSK31 signal?

What is indicated on a waterfall display by one or more vertical lines on either side of a data mode or RTTY signal?

Which of the following describes a waterfall display?

What does an FT8 signal report of +3 mean?

Which of the following provide digital voice modes?

Which of the following factors determine the characteristic impedance of a parallel conductor feed line?

What is the relationship between high standing wave ratio (SWR) and transmission line loss?

What is the nominal characteristic impedance of “window line” transmission line?

What causes reflected power at an antenna’s feed point?

How does the attenuation of coaxial cable change with increasing frequency?

In what units is RF feed line loss usually expressed?

What must be done to prevent standing waves on a feed line connected to an antenna?

If the SWR on an antenna feed line is 5:1, and a matching network at the transmitter end of the feed line is adjusted to present a 1:1 SWR to the transmitter, what is the resulting SWR on the feed line?