Antenna height importance

In earlier days while being new to operating it was fully satisfactory
to make the contact, log it, and move to the next one. Only much later
it became more interesting to search for what is behind it, what sort of
conditions, and to quantify signals or levels as a reality check for
the used technology. For some years I have advocated that a single
antenna is not enough on any band if one wants to optimize the use
of all possible propagation conditions. Actually, even two antennas
may not suffice (talking about independent radiators, not stacks).

WSPR is truly an excellent tool to get a feeling for the importance of
antenna height. The effect is most outspoken in a nearly ideal environment,
like at the seaside, where height is well defined due to a pure sea reflection.
Talking about horizontal polarization here (vertical is quite a bit trickier).

At 10 MHz two horizontally polarized antennas will show perfectly the
difference in SNR between the two antennas with varying take-off angle
when placed at e.g. 15 meters height and 30 meters height. The higher
antenna will have a sharp null in its vertical radiation pattern where the
lower antenna has its maximum. Two parallel WSPR-receivers are needed
to record signals from both antennas for SNR comparison. It will not give
absolute values, but show clearly how much better the other antenna will
be, either way, for an incoming station under momentary stable conditions.

I wonder if anyone has done this so far with WSPR. In normal operating the
effect is evident by simple selection out of multiple antenna heights, when
available at the operating location. Surely basic RX-SNR can be different for
each antenna in question, so no absolute conclusions can be drawn for
selecting the proper instant transmit antenna for any given propagation path.

73, "Zaba" OH1ZAA/OH2MZA