I think the point Mike is trying to make is that many SWR meters don't actually measure SWR all that accurately as impedance changes. While the length of transmission line doesn't affect SWR (other than the effect of loss), the impedance at a given SWR does change with line length, and that may cause the indicated SWR to change with some instruments. I wonder if an antenna analyzer, which actually measures impedance, and calculates SWR from that, would do any better. If it measures impedance accurately, it should.

73,
Scott K9MA


On 11/27/2018 21:34, Wes Stewart wrote:
I fail to see what that will prove. The only length that will do anything exciting is the 1/4 wavelength line and even that doesn't affect the SWR.  The other two will just repeat (less loss) on the input side, what terminates the load side.

Wes  N7WS

On 11/27/2018 3:51 PM, Michael Walker wrote:
If you truly want to understand SWR, I recommend you pick a frequency and
make up a 1/4, 1/2 and 1 wavelength sections of 50ohm coax.

Then measure the SWR at those points into various different resistive
loads, like 10, 25, 50, 75, 100, 150 and 200 ohms.

I think you will find the results very interesting.

Mike va3mw


______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]


--
Scott  K9MA

[email protected]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]

Reply via email to