[TenTec] Orion II AT tuner question

[Dr. Gerald N. Johnson]

On Fri, 2006-03-31 at 22:35 -0500, Carl Moreschi wrote:
> Of course what you said is true, but it is still better to have a matched
> antenna on receive.   There is always the possibility of very low atmospheric
> noise on a given night and the extra signal just might make the difference,
> especially on 10 meters.  Why do people insist on using a 9 to 1 balun on
> receive only beverage antennas?
> 
> Carl Moreschi N4PY
> 121 Little Bell Drive
> Bell Mountain
> Hays, NC 28635

There are cases where a matched antenna is a benefit, where the receiver
noise isn't so good. Most users of 10m antennas already build them
pretty well matched, because matching at the transmitter end of the
feedline makes the transmitter happy but doesn't guarantee the largest
radiated signal, mostly because of the added losses of the transmission
line with significant VSWR.

And then there are situations were maximum signal to the receiver is the
worst of conditions. Because it allows the local signals to overdrive
the receiver obscuring the desired weak signal by clipping or by
reciprocal mixing due to phase noise. Or there's a thunderstorm in the
state or closer doing both of those. Something the NR and NB won't
handle and the ringing Collins filters can't hack. Then its handy to
reduce the power from the unwanted signals sacrificing the desired
signal, hoping to remove the bad effects of the unwanted signals before
loosing that weak desired signal.

-- 
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer