On Christmas eve, I sneaked into the shack for a few minutes to seek shelter
from the grandkids, and, I turned on the 2 meter rig - an FT-847 - the VFO
of which was sitting on a beacon frequency I often monitor. Whoa! Talk
about noise! What I heard and observed on the rig's S-meter was really
something. The noise was semi-random, but, even the digital S-meter never
managed to drop below S-9. There were pronounced peaks of a few tenths of a
millisecond in duration, and, these, at three-to-five per second intervals.
The noise was audible from 138 thru 155 Mhz - which is the limit of what
knob-spinning I engaged in.
My first thought was, of course, some new type of line noise had invaded the
neighborhood, so, I twirled the antenna - a modified Cushcraft 3219 yagi -
to determine the noise source's direction. It was the same around the
compass with no peaks. Next, I hosed up the HF rig and listened on 40, 30,
20, 17, 15, 12 and 10 meters. No noise to be heard, save for the usual
low-level line noise I'm plagued with. Finally, I hooked up the 50 MHz
antenna to the FT-847 - the antenna being a 2 ele quad. No noise there,
For a moment or two, I was truly bewildered, and, wondered if the rig,
itself, might be the culprit... I need to add, here, that the weather was
abominable at this time - moderate to heavy rain, the drops seemingly
abnormally large, and, it was cold - near freezing, but, enough above that
temp so that no ice was forming. The wind was pretty gusty. In short, it
was a miserably cold, wet winter day.
So, as I sat pondering the new RFI situation, it occurred to me that what I
might have been experiencing is what, from time to time, I have seen
discussed on this reflector: Rain Static (?)
This theory was later supported by the immediate cessation of the RFI
coincident with the cessation of the rain.
So, all of the above is presented to ask the question: Does what I describe
accurately depict what one might find in a rain static situation? And, if I
may ask a follow-up question: I've had this old CC yagi up for many years -
it's probably well into it's 25th year. I've never heard anything like this
RFI before...from any antenna, much less, this particular array. What might
have changed, d'ya think? Oh - and, the antenna 'plays' as well as it ever
has - no changes in the measured parameters, at least from the rig end of
the coax cable.
73, Brad, W9FX
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