View Single Post
  #274   Report Post  
Old July 9th 15, 06:35 PM posted to rec.radio.amateur.antenna
[email protected] jimp@specsol.spam.sux.com is offline
external usenet poster
 
First recorded activity by RadioBanter: Jun 2006
Posts: 1,898
Default An antenna question--43 ft vertical

Jeff wrote:

Can you measure VSWR on a 1 meter long Lecher line at 1 MHz?


VSWR is not meaningful in such a situation, however, you can measure
return loss and Reflection Coefficient etc.. Of course that in not to
say that VSWR is not used in situations where it is not appropriate in
order to indicate how good a match is, when RL or Reflection Coefficient
would be more appropriate.

Jeff

Jeff


Are you trying to say that VSWR is not meaningfull at 160M (to put it
in an Amateur context)?

For those that don't know, a Lecher wire is just a carefully contructed,
rigid parallel transmission line upon which one would slide a high
impedance sensor to find voltage minimum, maximum, and where they
occured. That and a Smith chart were used to solve transmission line
and impedance matching problems and were often home built by Amateurs
in the early VHF days.

Today you would use a VNA (Vector Network Analyzer).

--
Jim Pennino