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VSWR doesn't matter? But how about "mismatch loss"?

C

Cecil Moore

Jan 1, 1970
0
Tom said:
Duh, life always violates it locally, but makes the sum total of entropy
higer than it would have been. You aren't the idiot you appear, I hope.

I guess I should have added a smiley face.
 
J

joseph2k

Jan 1, 1970
0
Cecil said:
Real-world antenna tuners do have a loss but we previously
specified a lossless system. Of course, real world tuners
and transmission lines suffer losses but we all just live
with those losses while striving to minimize them. The point
is that an antenna tuner reflects most of the reflected
energy back toward the load thus accomplishing a mismatch
gain that offsets some, if not most, of the mismatch loss.
High SWR transmission lines are indeed lossier than flat
matched transmission lines of the same material.
Close but no cigar. The (now often automatic) antenna tuner is used to
transform the native impedance to the transmitter to match the conjugate
transformed impedance of the antenna at the transmitter end of the
transmission line. The effective result is that the incident energy
arriving at the antenna "sees" a matched load and goes out to free space
instead of bouncing off the transmission line to antenna interface.
This is also why better antennas have reasonable (not far off matching
impedance) characteristic impedances; they do not require matching networks
physically placed at the antenna itself.
 
J

joseph2k

Jan 1, 1970
0
Cecil said:
Hi Buck, Please check out my associated web page and then
ask me anything that you don't understand.

http://www.w5dxp.com/notuner.htm

Contrary to what you may have been told, you can change
the 50 ohm SWR seen by your transmitter by changing the
length of the 450 ohm ladder-line.
Now that is a "real" ham radio antenna system, screwampus but it provably
works, and is repeatable (by others).
 
J

joseph2k

Jan 1, 1970
0
Richard said:
On 29 Mar 2007 13:10:46 -0700, "billcalley" <[email protected]>
wrote:
It does matter if you lack a tuner (in more ways that one). Most
discussion of "mismatch loss" omits such matters as tuners as it is a
separable issue. Combining these topics raises your chance of
confusion.

73's
Richard Clark, KB7QHC
Heartily agreed.
 

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