Amateur Extra › E9 Antennas and Transmission Lines › E9E06
E9E06
Which of these transmission line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm feed point impedance to a 50-ohm transmission line?
Pick an answer to check it.
Answer: C. 75 ohms
Q-section impedance = square root of (Z1 x Z2) = sqrt(50 x 100) = 70.7 ohms. Common 75-ohm coax is the closest choice.
Tip: Q-section: square root of Z1 x Z2.