SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/hamg-g9a03

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

450 ohms.

Start playing free

  1. 75 ohms
  2. 450 ohms ✔
  3. 100 ohms

Why: Window line has a nominal characteristic impedance of 450 ohms. Most amateur coax is 50 ohms, so the two do not match directly.

Huh, didn't know that: The characteristic impedance of a parallel conductor feed line depends on the spacing and the radius of the conductors.

The dad joke
Window line has a great view and an impedance of 450 ohms.
Like this card?
Play the game

References

Answer: 450 ohms. Window line has a nominal characteristic impedance of 450 ohms. Most amateur coax is 50 ohms, so the two do not match directly.

  1. NCVEC 2023-2027 General Class Pool and Syllabus (6th Errata, Feb 4 2026) ncvec.org/downloads/General%20Class%20Pool%20and%20Syllabus%202023-2027%20Public%20Release%20with%206th%20Errata%20Feb%204%202026.pdf
    D. 450 ohms
    Checked 2026-10-11.
  2. NCVEC 2023-2027 General Class Pool and Syllabus (6th Errata, Feb 4 2026) ncvec.org/downloads/General%20Class%20Pool%20and%20Syllabus%202023-2027%20Public%20Release%20with%206th%20Errata%20Feb%204%202026.pdf
    The distance between the centers of the conductors and the radius of the conductors
    Checked 2026-10-11.

Think this answer is wrong? Tap "Challenge this answer" on the card in the game and tell us why.

Test yourself in the game

Ham RadioWhy do voltmeters have high input impedance?Ham RadioIn a series LC circuit, what happens to impedance when inductive and capacitive reactance are equal?Ham RadioWhat is the term for the inverse of impedance?

That's stuff everyone should know.