Extra Class

Which of the following HF digital modes can be used to transfer binary files?

Which of the following HF digital modes uses variable-length character coding?

Which of these digital modes has the narrowest bandwidth?

What is the difference between direct FSK and audio FSK?

How do ALE stations establish contact?

Which of these digital modes has the highest data throughput under clear communication conditions?

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by EME?

What characterizes libration fading of an EME signal?

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

In what direction does an electromagnetic wave travel?

How are the component fields of an electromagnetic wave oriented?

What should be done to continue a long-distance contact when the MUF for that path decreases due to darkness?

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

When a meteor strikes the Earth’s atmosphere, a linear ionized region is formed at what region of the ionosphere?

Which of the following frequency ranges is most suited for meteor-scatter communications?

What determines the speed of electromagnetic waves through a medium?

What is a typical range for tropospheric duct propagation of microwave signals?

What is most likely to result in auroral propagation?

Which of these emission modes is best for auroral propagation?

What are circularly polarized electromagnetic waves?