> Tom Rauch wrote:
>
> <snip>
>
> >
> >Move 1/4 wl further to 1/2 wl and SWR will still remain 1.5
> >but now the impedance is 50 0j ohms.
> >A 50 ohm bridge would show 1:1 but a 75 ohm 1.5:1.
All true ... however, if one is using 75 Ohm cable in a 50 Ohm
system (e.g., CATV hardline) then the multiple of 1/2 wavelength
shows a 1:1 SWR on a 50 Ohm bridge - exactly what is desired.
The 75 Ohm cable is operating with a 1.15:1 SWR and slightly
higher loss but compared to RG-213 the tradeoff may be worthwhile.
> >So you see, no matter where you measure SWR it is unchanged
> >unless you have used a different reference meter with the
> >transmission line Z0.
Correct, it depends on the "system" perspective.
73,
... Joe, K4IK
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|