Jay, Marcus, LF,
[email protected] wrote:
...
> There appeared to be a noticeable quiet spot in the
> waterfall between ~ 8 and 9 kHz. I didn't investigate
> if this was an anomoly in the system or if there happens
> to be a quiet spot at that frequency.
When sferics are weak or absent, I often see a "dark band" in that
region, even with a nonresonant antenna (for example an E-field probe
which is "flat").
Markus Vester wrote:
...
> Part of the discrepancy
> could be that published figures inevitably include the energy of the
> distict spherics, which may well contribute the dominant part of the
> average noise power.
Yes, and that is probably why ITU's published figures show such a huge
difference between summer and winter. The radio spectrum emitted by
lightning discharges has a broad "hump" around 10kHz so it is a good
idea to hurry up with the experiments now before the northern hemisphere
moves into the QRN season. ;-)
73
Johan SM6LKM
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