On 27 Dec 2005 20:33:15 -0800, "RHF"
wrote:

Hello - Calling R2000SW and Telamon Where Are You ? ?

The Topic has move to the "Impedance of the Transmission Line"

IIRC - If the Matching Transformer is used and the Secondary Side
of the Matching Transformer exhibits a nominal Impedance of 50 Ohm;
and is connected to a 50 Ohm type Coax Cable; that is connected to
a Receiver's 50 Ohm Antenna Input.

The Coax Cable for all practical purposes is not a significant part
of the Impedance Relationship (Ratio) between the Antenna and
the Receiver's Antenna Input.

The Primary of the Matching Transformer 'helps' to smooth-out
the variations in Impedance of the Antenna due to changes in
Frequency with respect to the Receiver's Antenna Input Circuit.

Only point I was making is the impedance of the antenna could be
anywhere from a few ohms to thousands of ohms. A 9-to-1 balun between
the antenna and a 50 ohm transmission line only helps if the antenna
is in the neighborhood of 450 ohms.

The Impedance Matching improvement is far from perfect :
But the Dynamic Range of the Front-Ends of most Modern
Shortwave Receivers can easily compensate for any signal
lost due to Impedance Miss-Matches between the Antenna
and the Receiver's Antenna Input Circuit.

With that much dynamic range, why use a balun at all?

hey I could be wrong - cause iane ~ RHF

I can be wrong, too. Antennas are complicated beasts :-(

bob
k5qwg
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