Actually, in describing GSh mode, I used "narrow" and "wide" beam in a different sense!
"wide angle" antenna means = larger or at least equal diagram of reception than that of a "narrow beam" antenna in a particular plane.
So, in case of GSh, azimuth (beta) plane... (vertical x horizontal)
P-11V antenna, main lobe diagram 7.5 x 1.1 degrees P-13V antanna, main lobe diagram 1.7 x 1.7 degrees
Note that the angles for P-11/P-13 antennas in beta-plane are
1.1 < 1.7!
So, the arrangement is as follows:
main channel receives from P-11 (which is usually called "wide angle") aux channel receives from P-13 (when it is not transmitting) (which is usually called "narrow angle").
Now you see why the roles of P-11/P-13 are (as "wide"and "narrow" beam) are, technically speaking, reversed!
The same is true for vertical (epsilon plane), using P-12/P-14 pair as main/aux receiving antennas.
