[Lowfer] WM too bright!

[John Andrews]

John, Bill,

>some
> broadcast engineers attempting to measure soil conductivity in the AM band
> by means of signal attenuation noted that their conductivity results came
> out on the high side during very cold winters.

Amen. The difference can be impressive. Over the lousy ground here in the
Northeast, smart AM guys see that their initial field strength measurements
are made in the winter. That way, when the FCC sets the limits on their FS
monitoring points, the station should be safely under them all year.

That said, AM field readings can vary dramatically with temperature over a
time frame that's much too short to be explained by the ground, trees, or
anything but the air. I've never seen a convincing explanation of that
effect. But I've observed days in January where the weather was balmy in the
morning and very cold in the afternoon following a frontal passage, and
local AM field readings went right up with the temperature.

John A.