Hi Steve,
> Ron's (KK1L) statement:
>
> "Now wouldn't this also mean that you are creating a nice reflection
> back up the line to the antenna? This should provide more power at
the
> antenna for it to radiate."
>
> Most tuners will totally dissipate the reflection such that it will
> not be delivered to either the transmitter or the antenna.
Nonsense.
You've just totally wiped out any form of impedance matching using lumped
components in a few clicks of the keyboard. Not only that, you've stopped
most of the antennas your company sells from working! Loading coils,
matching stubs, and even antenna elements themselves would all quit working
if what you said was true. It would be a one impedance world, without power
factor correction in our electrical distribution systems.
If we have a 3000 ohm line, and couple it to a 50 ohm line, the SWR at the
junction is 60 to one. According to your statement the matching network
would dissipate nearly all of the applied power.
The statement made above about tuners dissipating power would be true if
they matched with resistors, but not with typical Q inductors and
capacitors. Most matching systems achieve efficiencies well over 90%,
unless the ratio of loaded Q to unloaded Q is extremely high.
Let's not mislead people trying to understand how systems actually work!
Tuners DO NOT dissipate the reflected wave, they simply re-reflect it until
the system is in equilibrium.
73 Tom
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|