Extra Class Practice Examinations (8 of 8)

Finished chapter 4, Amateur Radio Practices in the American Radio Relay League (ARRL) Extra class license manual. There are five questions on the exam regarding Amateur Radio practices and I scored 94 percent on element four.

Definitions of Interest According to License Manual (p 3-27,28).

• Bandwidth is, "Frequency range measured in hertz (Hz) over which a signal is stronger than some specified amount below the peak signal level."
• Conducted noise is, "Electrical noise that is imparted to a radio receiver or transmitter through the power connections to the radio."
• Dynamic range is, "An ability of a receiver to tolerate strong signals outside the band-pass range."
• Noise floor is, "A receiver input signal that produces an audio output of the same strength as the internally generated noise in the receiver."

I enjoyed reading about receiver performance concepts especially the front-end and distortion effects leading to blocking. According to the manual, "The theoretical noise power at the input of a receiver with an input-filter bandwidth of 1 hertz is a -174 dBm." (p 4-18)

A -174 dBm is the best possible noise floor for a receiver as suggested by the manual.

This chapter helped me understand my Yaesu FT100 receiver a little more. Good stuff and now I'm going into Chapter 5, Electrical Principles and I'm ready for a neuron bending experience.

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