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Old December 11th 03, 10:02 PM
w4jle
 
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As most of us do not transmit in the audio range, your own data shows a
range of 50 to 47.8 Ohms for normal ham use. Close enough for government
work, at least as far as I am concerned..

"Reg Edwards" wrote in message
...

"Reg Edwards" wrote in message
Zo of ALL real, ordinary, transmission lines changes versus frequency

over
a
very wide frequency range.

Zo ranges over lots of thousands of ohms at a few cyles of seconds,
thousands of ohms at power frequencies, hundreds of ohms at audio
frequencies, and from tens to a few hundred ohms from 100KHz up to as

many
GHz as you like.
---
Reg.



Are we talking the same thing for Zo ? That a piece of say rg-8 (

whatever
they want to call it now) that is 50 ohm coax is not 50 ohms over its

normal
operating frequency range ?

=============================

What is your normal operating frequency range?

Here is Zo typical of cable similar to RG-58 versus frequency.

Nominal Zo = 50 ohms.
Degrees = Angle of Zo.

Freq Zo Degrees
------ ------- -------
10 Hz 3000 -45.0
100 Hz 950 -44.9
1000 Hz 301 -44.1
10 KHz 97 -36.4
100 KHz 54.2 -10.1
1 MHz 50.0 -2.6
10 MHz 48.4 -0.84
100 MHz 48.0 -0.26
1 GHz 47.8 -0.08

Superimposed on the above Zo vs F characteristics are manufacturing
reel-to-reel variations of 2 or 3 percent.
----
Reg, G4FGQ