Amateur DX Europe to Alaska on VLF?

There has been some excitement over the last few days as Lawrence KL1X has seen a signal on 8.9700kHz when the noise was low that just could be coming from Uwe DJ8WX near Hamburg. He has tried to find out if this is a locally generated artifact, but it seems not.

KL1X grabber monitoring 8.270kHz for intercontinental amateur DX

In the coming weeks DJ8WX is moving his continuous carrier VLF transmitter (a long carrier is needed to be visible in the incredibly narrow bandwidths needed to see anything at all) down to 8.270kHz which is a clear frequency in Alaska. The Alaska VLF grabber is already active and, as soon as Uwe starts up, we hope to see a weak signal appear. If this happens this will be the very first confirmed reception of an amateur VLF signal from Europe in North America. The VLF receiver Lawrence uses is a small E-field probe antenna high up in a tree in a birch forest.

DJ8WX has been a very good signal on VLF here in the UK on my own receiving system (an 80m sq vertical loop feeding a preamp feeding a PC running Spectrum Lab with a special 424uHz bandwidth .usr file). I have not listened for Uwe recently as my loop is down but G3ZJO has copied him well in the last few weeks on his grabber.

DJ8WX's signal as seen on the G3ZJO VLF grabber

If you are interested in amateur VLF then visit https://sites.google.com/site/sub9khz/ and check out the various preamps, grabbers and DX reports. It is possible to check out activity by looking at the various grabbers (VLF receivers linked to the internet) around the world.

More VLF activity from Germany

DJ8WX has been experimenting with a new GPS locked frequency source and is trying to put a signal out on 8.9700000kHz.  The signal has been received strongly by several stations including Paul Nicholson in Todmorden and at PA1SDB. This is the signal at PA1SDB over the last few days. Note the timescale on Peter's grabber covers several DAYS. Such is the world of amateur VLF!

Signal from DJ8WX now on 8.970000kHz (was 8.970022kHz)

8.97kHz VLF amateur activity

DJ8WX's VLF signal received by G3ZJO (frequency is Hz)

This last week or so Uwe DJ8WX has been active again on VLF from his location near Hamburg.  Uwe was the strongest signal I ever copied on the so called "Dreamers Band" a few years ago and his signal is being well received again now. To copy these signals at 8.97kHz requires a quiet antenna location and a very stable, frequency locked receiver. You will NOT be able to hear anything and signals take hours or days to appear on the PC screen using a package like Spectrum Laboratory. Getting a very very stable receiver is actually easy as Spectrum Lab can lock onto one of the strong MSK VLF commercial signals and use this, or a GPS signal, as a very accurate reference. Much more details on the Sub-9kHz Amateur Radio pages.

DJ8WX copied again on VLF (645km)

Uwe DJ8WX is currently transmitting a long dash on 8.90022kHz and his signal was copied well on my VLF grabber overnight in a 424uHz bandwidth. Also visible is a mystery signal around 8.9701kHz that most people think is some sort of local noise source but it is very repeatable every night.

DJ8WX on 8.970022kHz again

Just weak a very weak trace overnight (you have to look hard!) from DJ8WX on VLF. Compared with his signals a few days ago he is at least 10dB weaker. Not sure why as nothing has been changed here. G3ZJO also copied Uwe weaker than before, although Eddie was getting him slightly better than me using his E-field probe antenna. By the way, this small trace (in blue/white) covers a period of 8 hours and is looking for the signal in an incredibly narrow 424uHz (yes you read it correctly - microhertz) bandwidth.

DJ8WX received on 8.970022kHz

DJ8WX on 8.970022kHz VLF (645km)

Overnight tonight I received a new station on VLF:  Uwe DJ8WX who is 645km east of me. Uwe was a solid signal here in JO02dg in the early hours on 8.970022kHz. His signal level dropped off during the night somewhat but he was still visible at 0500z. Spectrum Lab settings were as for the G3XIZ reception the previous night with the FFT bandwidth set to 423uHz. This is the 4th ham station now copied at VLF in 4 unique locator squares and 2 countries.