First thing, 160 meter is NOT the Topband and hasn't been for a number
of years. 2200m is the Topband, with 630m in second place, and 160m a
distant third.
There are two areas of interest in the MF/LF/VLF world. Amateur and
non-amateur/SWL.
If you are primarily interested in just listening and logging many
interesting signals, you can spend a lifetime tuning below 500kHz and
never hear it all.
Just a few from the high end first approximate frequencies):
Navtex 512kHz
NDB 200-500 kHz
DGPS 300 Khz
LW Broadcast 200kHz +/-
WWVL and similar 60 kHz
Military data 10-35 kHz
Geophysical and atmospheric noises various VLF down to a couple kHz or less
If you are interested in amateur operations including experimental
transmissions there are a number of places to look.
630 meter band: lots of amateur activity here. Some CW but mostly JT9
digital. Several hundred station currently active worldwide. Lots of
WSPR activity with 630m reports exceeding those from 160m EVERY night!
From my rather poor Inland Northwest QTH, I have worked 120 unique
calls in 39 states and 7 DXCC so far. The power limit is 5 watts EIRP/
500 watts transmit power max. With a typical backyard antenna system
running about -15 to -20 dBi it might take the whole 500 watts to get 5
watts radiated. Not a band for the timid...
2200m band: lots less activity due to severe physical limitations. 1
watt EIRP/1500 watts transmitter power max. With typical backyard
antennas running around -30 dBi, you need a KW to get 1 watt radiated.
Probably less than one hundred active transmit capable stations
worldwide but many times more than that listening. Most work is WSPR
beacons but also JT9 QSO's. I have 11 stations worked in 8 states and 3
DXCC so far.
There is a no license low power band at 187 kHz approximately. I don't
know much about this one except there are a number of east coast USA
beacons running that I have never been able to hear.
There are several experimental stations that occasionally transmit WSPR
beacons on approximately 75 kHz. I have heard a couple of them out to
1000+ miles.
There are a few really motivated experimenters who transmit beacons on
about 8 kHz. I've never been able to hear any of them but I believe
signals have been copied across the Atlantic in the past.
If you want to know more about the 630 meter band look at :
https://njdtechnologies.net/
John provides a 630 meter daily report of activity plus lots of other
info to get you started.
73,
Larry - W7IUV
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
|