[Elecraft] Using K2 rant input

[Bill Coleman]

On Feb 11, 2005, at 12:13 AM, Vic Rosenthal wrote:

> I am experimenting with using the K2 rant input (that's receiver 
> antenna, not verbal outburst).
>
> I want to use my 20-meter quad as a receiving antenna when I am 
> transmitting on 160 with an inverted L.  It is a lot quieter.  The L 
> is right next to the quad, so a lot of voltage is induced in the quad 
> when transmitting with high power.

Vic,

I think you may be missing the point of using a separate receiving 
antenna on noisy bands like 160m.

While the 20m quad may be quieter, that's likely due to the smaller 
size and gross impedance mis-match of the 20m antenna on 160m. The 20m 
quad is probably quieter for ALL signals and noise alike, which doesn't 
help.

The key to using a separate receiving antenna on 160m is NOT just to 
have a quiet, lossy antenna -- but to have a quiet, lossy, DIRECTIONAL 
antenna. The idea is to improve the signal / noise ratio by limiting 
the noise intercepted at the antenna. Since noise is generally thought 
to come from all directions, using an directional antenna makes signals 
appear stronger.

The Beverage antenna is probably the most popular receiving antenna in 
this service, but requires a lot of real estate. For 160m, a Beverage 
would be about 500 feet long.

For those of us without room for such an antenna, the flag, pennant and 
K9AY loop are good substitutes. These antennas have a cardioid 
(heart-shaped) pattern, with a strong null in the opposite direction. 
Magnetic receiving loops area also useful, particularly for nulling out 
strong local noise sources.

All of these receiving antennas should be mounted well away from the 
transmitting antenna, to avoid the type of coupling you're having 
trouble with now, as well as to avoid noise reception due to mutual 
coupling. Since these antennas are intentionally lossy, it usually 
doesn't take that much distance to avoid transmitter overload.

Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
Quote: "Not within a thousand years will man ever fly!"
             -- Wilbur Wright, 1901