¿ªÔÆÌåÓý

ctrl + shift + ? for shortcuts
© 2025 Groups.io
  1. Nanovna-Users
  2. Messages
Single Messages Topics Expanded

Re: quick measuring cable characteristic wave resistance

 

Hi,

wave-theory of open transmission-line (Z_l = inf) is Z =
-jZ_line*cot(beta*len_line).
If the line has a length of the line is labda/8 this gives cot(pi/4), which
is one.

Thus we have Z = -j*ZLine | lengh_line = labda/8

And we have just the wave-impdenace of the line left in the equation.

Correct me, if I'm mistaken here please, but sounds like a clever idea :)

Best Regards,
Martin


Am Fr., 27. Dez. 2019 um 16:49 Uhr schrieb Corneliu via Groups.Io
<coralenka@...>:

Hi Hans,
Thank you vm for for sharing your method with us.
I do not know which is the explanation behind this method but I can
confirm it is working very well.
I have 2 pieces of professional made high quality 50 ohm cables about 38
cm long and they both measured 50 ohms +/- 0.1 ohms.
The cables supplied with nanoVna measured 53.7 and 55.2 Ohms respectively.
Thank you very much!
Merry Christmas!
73! de YO4AUL
Join [email protected] to automatically receive all group messages.