(Prompted by Re: Topband: Good Conditions, little NA Activity)
How much the conditions at ELF frequencies parallel the conditions at 1.8
MHz, I can't say. However, I noticed last evening that many lightning
receivers in Europe were picking up lightning strikes SW of Central America
in the Pacific Ocean. Were conditions as good on 160 meters as they were
at ELF?
Those very long distances are not that common in the lightningmaps.org
worldwide lightning detection network. Propagation was very significantly
enhanced at these ELF frequencies, from about 15 kHz up to 60 kHz.
Could this also be an indication of Topband conditions? Please try it, and
let us all know! :-)
You can view those strikes and propagation conditions at lightningmaps.org.
You'll see individual lines drawn on a world map, from the individual
strikes to the distant receiving stations. Adjust the Lines setting in a
drop-down menu on the right to 3 or more. Also, in a menu on the left,
select BOTH lightningmaps.org AND blitzortung.org.
These custom SDR lighting receivers --which constantly send strike location
and GPS- based timing and station location information to the
blitzortung.org servers in Europe-- *use very small broadband loop antennas*.
The majority of them use ferrite rods and vertical wire probes less than
10" long! Others use two or three 2-to-4 turn wire loops, a meter or less
in diameter (which I use on my stations #1977 and 2294), instead of the
ferrite loop antennas. That indicates just how sensitive these receivers
are.
Due to health conditions and obligations, I am not now in a position to
compare ELF conditions to those on 160m. I hope a few reading this will,
and share their observations here.
Discussion forum: https://forum.blitzortung.org
Other website: https://www.blitzortung.org
73, Mike
W0BTU
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