[Elecraft] Dual Receiver Tricks

[Jim Brown]

Some words are being misunderstood and mis-used.

Polarization describes the geometric orientation of the antenna and the 
resulting EM field. Polarity is the positive or negative going sense of 
voltage or current in a circuit (what for decades we mistakenly called 
"in phase/out of phase).  Polarity has two values, positive or reverse. 
We change the polarity by turning the wires over in a circuit.

Phase is a continuously valued function and is measured in degrees or 
radians. The phase relationship between two signals has meaning only for 
sine waves of the same frequency. The phase relationship between 
antennas is a function of the distance between them, the frequency of 
each signal they transmit or receive. Further, this phase relationship 
is different for every angle from which a signal arrives or to which it 
is transmitted. The phase relationship also includes the electrical 
lengths of the transmission lines involved, and, of course, the 
difference in phase increases in proportion to the frequency of the signal.

There's a tutorial discussion of these concepts in 
http://k9yc.com/VE3DO.pdf in the context of how the DX Engineering NCC-1 
and NCC-2 work to steer the directivity of two spaced antennas. The same 
laws of physics are at play in this discussion.

73, Jim K9YC

On 6/26/2019 9:20 PM, Edward R Cole wrote:
> I feed signals from two antenna that are orthogonally polarized (one 
> is horz and other is Vert polarity, both pointed in the same direction 
> and essentially in-phase).
> I use the eme sw MAP-65 to process the output of both Rx and it 
> resolves the angle of polarization and maxes signal strength in 
> alignment with the actual angle of polarity.