Hi all,
Just found this very interesting site and it looks like a fun thing to do. I see that there are lots of UK stations already but a fairly large gap in coverage between the Manchester area and Edinburgh. I'm in central Cumbria, up near the Scottish border, so more or less midway between the existing stations. I have a very quiet rural location and plenty of room to experiment with antennas, etc. Like many on here, I am a radio amateur, active on HF CW. I'm also a light aircraft owner/pilot, so I have more than a passing
interest in the weather.
Would a station up here be of value, or is there already sufficient coverage in the UK?
Regards,
John
G3WGV
Hello John and welcome.
There are no restriction for installing a station. If you want to then, just bought the kit (when available).
You should know that the more stations are installed the best is the coverage.
If I was at your place, I would definetly set up a station there.
Btw, you can check coverage at
http://www.lightningmaps.org/extra/cover...%5D=1#cmap (but don't know if it is updated).
Thanks Clément. I've done some more research and it does look like a station here might be useful. Once the initial rush is over for System Blue I'll get one and aim to set it up in time for next year's thunderstorm season.
John.
John,
Your location would be a godsend.
We have no stations from here , just north of the River Tay down to the Humber.
Chris
Thanks Chris. It's a bit of a shame I didn't discover this earlier as I'd have quite enjoyed building the System Red. Never mind, I'll happily join the swelling ranks waiting patiently for Rhapsody in Blue and look forward to it as a winter build project. *Thinks* yet another GPS-trained pulse generator running here - about time I came up with a more integrated solution to reduce the number of GPS antennas!
How close would your station be to the Anthorn VLF transmitter?
I'm about 50km SE of Anthorn. Hopefully far enough away for it not to be a problem. Skelton is only about 25km away and that too has VLF transmitters, for purposes that I couldn't possibly comment on. Perhaps a high Q notch filter will be in order.
As a further thought, do high powered VLF transmissions affect this system in any deleterious fashion? NPL's 60kHz MSF is a keyed carrier wave transmission but the rise/fall times are quite slow. Skelton's VLF transmissions at around 20kHz are probably some sort of FSK (I really should take a listen). In both cases I expect the biggest problem would be amplifier blocking due to high signal strength rather than any sort of pulse detection anomalies.
I'm mindful of the need to avoid any circuitry in the antenna system that might affect timing, such as resonances within the VLF spectrum. This makes it difficult to reject unwanted signals - effectively the system is a baseband receiver with a few 10s of kHz bandwidth. Perhaps notch filters could be added, since these are in effect anti-resonances, but I don't know what unwanted side effects they might have. Fabricating something with sufficiently high Q would also be an interesting engineering challenge!
(2015-09-03, 10:53)G3WGV Wrote: [ -> ]As a further thought, do high powered VLF transmissions affect this system in any deleterious fashion?
VLF transmitters are a problem, but:
- magnetic antennas are directional, you can align them to supress one direction
- VLF transmitters have a very narrow spectrum. If it comes to spectral energy density, lightning strikes are on a broadband receiver much more powerful. So you may just need to reduce your gain and you can still detect strikes
It'll be interesting to see how this all works out when I can get my mitts on the kit. In the meantime I may just knock up a loop antenna, attach it to a baseband amp and see what signals my 'scope shows. Apart from some tinkering with MSF on 60kHz I've not really experimented with VLF before. But I've been playing with radio throughout much of the rest of the spectrum for 50-odd years.
John.
My station is about 60km south of the Inskip 81kHz transmitter, and I get a very clear noise peak at that frequency. My H-field antennae are aligned roughly N-S and E-W (not for any technical reason, other than that the corner of house is so aligned!), and I have noticed that the gain I can manage on the N-S axis is consistently quite a lot lower than E-W, and I had always assumed that that was due to the big peak from the transmitter. However the transmitter was turned off for couple of weeks in August and although the spike disappeared my gains didn't improve, so I guess it's not that after all! I'm about 3km north of Fiddlers Ferry Power Station (2 GigaWatts), and I'm wondering whether that may be to blame.
I still get quite reasonable results in a suburban location though, your location should be useful. Farm electric fence controllers can sometimes be an issue in rural areas.
Andrew
Thanks for that Andrew. I'm getting the materials together to build a coax loop (or perhaps just a wire one, haven't decided yet which is best?) and will take a look at what it picks up on my 'scope. Did you consider trying to get rid of the 81kHz signal with a series tuned circuit (notch)? Perhaps it doesn't matter, as the signal is not a broad-band pulse and I would imagine the controller has some sort of algorithm to reject non-pulse signals. Of course the VLF transmission might be strong enough to block the amplifier, forcing a gain reduction.
We do have electric fences around here occasionally. I hear their regular "transmissions" on the LF bands on my amateur radio station and they are very sharp spikes - easily eradicated with the noise blanker, unlike lightning.
(2015-09-02, 08:28)DelandeC Wrote: [ -> ]Hello John and welcome.
There are no restriction for installing a station. If you want to then, just bought the kit (when available).
You should know that the more stations are installed the best is the coverage.
If I was at your place, I would definetly set up a station there.
Btw, you can check coverage at http://www.lightningmaps.org/extra/cover...%5D=1#cmap (but don't know if it is updated).
Hey guys,
I am interested as well, and I don't think there are receivers very close to me:
Latitude
29.210193 (29° 12' 36'' N)
Longitude
-98.314184 (98° 18' 51'' W)
Please let me know when I can buy a kit...
Thanks
jerry
wy8s
jrnokes@gmail.com