HAM - Radio Extra Class Test Radio Extra Class 1

Question 1

What is the input impedance of a quarter-wavelength transmission line section terminated with a short circuit?

Accepted Answer

Infinite impedance (open circuit)

Answer

0 ohms (short circuit)

Answer

Purely resistive and equal to the line's characteristic impedance Z0

Answer

Z0 squared divided by the terminating impedance

Question 2

Which filter design exhibits a maximally flat amplitude response throughout the passband, sacrificing roll-off steepness to eliminate ripple?

Accepted Answer

Butterworth

Answer

Chebyshev Type I

Answer

Elliptic (Cauer)

Answer

Bessel

Question 3

What is the lowest frequency in the 80-meter band at which an Extra class licensee may operate single-sideband phone?

Accepted Answer

3.600 MHz

Answer

3.525 MHz

Answer

3.700 MHz

Answer

3.750 MHz

Question 4

What does a receiver's third-order intercept point (IP3) specification describe?

Accepted Answer

The theoretical input power level at which third-order intermodulation products equal the fundamental signal amplitude

Answer

The input power at which the AGC circuit reduces gain by 3 dB

Answer

The frequency offset at which spurious responses are 3 dB above the noise floor

Answer

The noise figure degradation caused by a 3 dB lossy input attenuator

Question 5

What is the approximate forward gain of a well-designed three-element Yagi antenna referenced to an isotropic radiator?

Accepted Answer

7 dBi

Answer

3 dBi

Answer

5 dBi

Answer

14 dBi

Question 6

What propagation advantage does operating during the 'greyline' provide for HF amateur radio communication?

Accepted Answer

Both ends of the path can simultaneously experience an absent D layer while the F layer remains ionized, enabling strong low-noise long-path signals

Answer

The F2 layer reaches its maximum height, allowing the highest usable frequency to peak

Answer

Sporadic-E clouds form preferentially along the terminator, enhancing 6-meter contacts

Answer

Tropospheric ducting is strongest along the day-night boundary, extending VHF range