View Single Post
  #38   Report Post  
Old September 4th 03, 08:00 PM
W5DXP
 
Posts: n/a
Default

Dave Shrader wrote:
Or, how about: one with an in'port' and the second with an out'port'?


Speaking of which, I just thought of a way to alleviate the confusion
about the earlier example which was:

------lossy feedline---x----10+j60 ohm load

I hope my memory is correct about the load value. If we add one wavelength
of lossless feedline to the experiment, we don't change anything but
things become a lot clearer.

---lossy feedline--+--1WL lossless 50 ohm feedline--10+j60 ohm load
Pfwd1-- Pfwd2--
--Pref1 --Pref2

It is readily apparent that Pref2 cannot be greater than Pfwd2.
If my math is correct, at the load, |rho|=0.85 and SWR=12.3:1
|rho|^2=0.7225 so Pref2 = 0.7225(Pfwd2)

The main thing to gather from the above example is that:

(Pfwd2 - Pref2) = (Pfwd1 - Pref1)

Therefore if Pfwd2 Pref2 then Pfwd1 Pref1

Conclusion: This is NOT an example of Pfwd Pref.
--
73, Cecil, W5DXP