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... not Russel! Registered Member #1
Joined: Thu Jan 26 2006, 12:18AM
Location: Tempe, Arizona
Posts: 1052
Anyone who hasn't had a chance, get your VLF antennas ready! SAQ will be firing up the historical Alexanderson alternator and transmitting on 17.2kHz on December 24th, 2007, at 0800 UTC. For anyone who doesn't know, SAQ is a VLF transmitter in Grimeton, Sweden, and transmits at a frequency so low that it would probably be audible to most people if it were sound instead of electromagnetic radiation. A radio is not required for reception -- just a big loop of wire, a sound card, and a program like Speclab.
I haven't had any luck with this so far, but Steve Conner was able to get great reception last time, and posted the results here. I'm hoping that my active whip antenna will finally be able to bridge the gap. Anyone else up for a go this time around?
... not Russel! Registered Member #1
Joined: Thu Jan 26 2006, 12:18AM
Location: Tempe, Arizona
Posts: 1052
Yes, VLF is very low frequency, the name for the band of frequencies between 3kHz and 30kHz. It's a great place to get started with radio in this day and age, since nearly everyone already has the equipment to receive 0-22.5kHz or 0-24kHz. Unfortunately, most of the man-made signals in this range are encrypted data links for use with submarines and other naval vessels -- doesn't make for interesting listening. The bright side is that there are many interesting natural signals to listen for, and once in a while SAQ fires up their transmitter, giving everyone a chance to receive some morse code.
Registered Member #286
Joined: Mon Mar 06 2006, 04:52AM
Location:
Posts: 399
I am ready! My antenna is a longwire running across the roof of the house. Also, I have also put together a 17.2khz active bandpass filter to filter out most of the other junk such as 60hz mains. Below is a snapshot of Spectran and I am picking up the 15khz horizontal frequency from a TV in the house.
... not Russel! Registered Member #1
Joined: Thu Jan 26 2006, 12:18AM
Location: Tempe, Arizona
Posts: 1052
Looks good! I'll post a screenshot of what I see in that area later this week, so you can see how they compare. At night, do you see any sign of the big military msk transmitters operating on 18.6, 19.6, and 22.1 kHz?
Registered Member #27
Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058
Generally anything that drifts in frequency is unintentional transmitters, usually local. Some times you can clearly hear that it is a circular saw or something similar by just listening to the signal.
The intentional transmissions are usually fairly narrow in bandwidth and at a very constant frequency. This picture show a typical and strong transmission at 18.6 kHz.
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SAQ Transmission - December 24th, 2007 - 0800 UTC
