billcalley wrote:
On Mar 29, 1:34 pm, Cecil Moore wrote:
billcalley wrote:
Since mismatch loss is the "amount of power lost due to
reflection", and is as if an "attenuator with a value of the mismatch
loss where placed in series with the transmission line", then I would
think that VSWR would *definitely* matter, and not just for highly
lossy lines either. But here again, I'm probably not seeing the
entire picture here. What am I missing??
If the system is Z0-matched, e.g. antenna tuner, there is
a mismatch gain at the tuner that offsets the mismatch
loss at the load so, in a lossless system, nothing is
lost. Wave cancellation toward the source is balanced
by constructive interference toward the load.
--
73, Cecil, w5dxp.com

Now my head *really* hurts! This is a VERY confusing subject, to
say the least. (And I also thought antenna tuners actually had a
*loss* due to their limited Q...I think I'm going to change careers
now and just become a pet groomer; or perhaps simply give up
completely and work at Radio Shack).

If you start considering loss in the tuner and the line then yes, a
greater mismatch between the antenna and the line will result in more
lost power (and more component heating in the tuner). You really want
to leave that subject be until you understand the properties of a
lossless system.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Posting from Google? See http://cfaj.freeshell.org/google/

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html