On 10/8/2012 8:56 PM, J. C. Mc Laughlin wrote:
Back when the Michigan State Police used 40 MHz, at some posts static
levels would become so high as to reduce range to almost nothing. Some
say it was precipitation noise (as is common with aircraft) and some
people believe it had another cause. It seemed to be weather related.

On 6 meters, with an AM circuit I had for years with my father, I have
heard discharge noise that starts with a sequence of pops and progresses
to a steady roar that occasionally would abruptly stop. (about 100 km
path with yagi antennas at both ends)

My guess is it was due to local, enhanced noise. Effects may have been
suppressed due to the nature of FM and its mode of squelching. 73, Mac N8TT


That noise sequence is exactly what I hear when I see a corn snow squall
come through my property in the winter. I have actually watched the wind
blown snow come closer and closer while the HF radio noise increases
until all signals are wiped out, then when the back edge of the squall
passes the antenna, all is quiet, again.

I live at 2800 ft in the Central Oregon desert. The antenna is either a
ground mounted 5BTV with 40 radials, or a 160 meter horizontal loop at
35 ft.

Paul, KD7HB