Topband: Skimmer calibration

[Tom W8JI]

> Do we really care that skimmers aren't hooked up to antennas with
> pattern and gain?  One of the things in using VOACAP is knowing the
> pattern of the RX antenna as well as TX. Omni pattern at RX removes RX
> antenna bias.  Why shouldn't we specifically use omni on RX, so that
> any enhancement is from the sender or the propagation/environment?
>

If I wanted to know what antenna was better, I would use a short vertical or 
vertically polarized antenna for most applications.

Ideally, you want a broad elevation pattern with no nulls. A 2 foot vertical 
has about the same pattern as a 130 ft vert for elevation on 160, so the 
only issue is sensitivity falling into RX internal noise.

I think people live on the false notion that verticals have a null at near 
zero, which patterns on Ham models will show, but that is a program display 
shortfall causing that error. If they really were zero, all broadcast 
stations would be dark for groundwave. :)