Lightning Detectors

[Dispatrick]

I'm looking for additional info on what frequencies lighting detectors use to communicate and or send out alerts to other detectors in its coverage area.

There's one in a park near my house and I believe it is a WX Line WaveSiren. I found some specs and found it uses 27.2550MHz to communicate with other detectors at the park to set off the sirens.

I'll be plugging in the frequency to see if I hear anything (probly a data burst) when inclement weather comes though the area.

 

[w2lie]

You might be able to parse some data is you use a SDR with rtl_433

frequencies to put in are 433mhz, 315mhz and 915mhz, if my memory is correct.

 

[kruser]

Many of these systems have just one 'detector'.
When the sensor (detector) detects nearby lightning, it sends signals to one or more remote horns or strobe lights. This is the signal you would hear.
Lightning can be detected over 100 miles away and using small but special antennas containing several wire wound ferrites oriented in different directions, can become directional which is used to give the user an idea of the storms direction on some detection systems. Overall signal strength can determine distance of approaching storms.
I have an old detection system that was used at airports made by BFGoodrich Flight Systems WX-110. Although it was made about 1991, it is amazingly accurate to this day.

The system you may be talking about was probably designed by Thor Guard in Florida. Thor Guard, Inc. - Lightning Prediction and Warning Systems
I installed and maintained several versions of their systems over the years at the country club I worked at.
I'm pretty sure Wxline uses the same technology. Thor Guard is a much older company than Wxline.
I must guess both companies use the same basic technology.
They had a single sensor for detection. The sensor could hook directly to a small custom processor for analysis or it used a low power 902-928 MHz ISM band link to the processor if located in a remote location away from the sensor. That radio link contained encrypted and proprietary data.
The analysis computer was custom to Thor. It could activate local sirens attached directly or they used one of the CB Band frequencies that was never assigned as an actual CB voice channel. I forget what class those were considered but I think their purpose was intended more for toys and remote car alarms and cheap RC airplanes and cars etc. Not really very professional for a company like Thor in my opinion whom invested a ton of money in the rest of the system but used CB band frequencies to signal the remote horns to sound.
One thing interesting was that they used FM emission plus they offered a high power (20 watts maybe) version of the 27 MHz transmitter for use in large areas like a 250 acre golf course or superspeedway like Daytona.
I never got to see the FCC ID for the high power transmitter as I retired prior to the club switching to that. I always questioned if it was legal or not.
I only know it still used the same 27 MHz frequency as the remote receivers did not need to be swapped out.

Anyway, the 27.255 frequency you found may be correct but it will probably be FSK sounding data using FM emission.
And that will only be the signal that activates the remote horns or sirens. The FSK data basically just contains an ID set by the user so the receivers don't false trip. There can also be some diagnostic data that can be sent which doesn't sound the horns or strobes but that's usually only used during annual testing and setup.

These systems are fairly popular at parks and other outdoor events and venues like large ball stadiums. car races, golf tournaments, outdoor amphitheaters etc.

 

[W4UCK]

I have an Ambient weather station and I haven't figured out exactly which data burst is the lightning detector, but its telemetry is at 915 + and - a few KHz. The lightning detector is only once every 80 seconds, so its a bit hard to catch. Its an extremely brief chirp.

Jim

 

[KE5MC]

...snip...
Lightning can be detected over 100 miles away and using small but special antennas containing several wire wound ferrites oriented in different directions, can become directional which is used to give the user an idea of the storms direction on some detection systems. Overall signal strength can determine distance of approaching storms.
I have an old detection system that was used at airports made by BFGoodrich Flight Systems WX-110. Although it was made about 1991, it is amazingly accurate to this day.
...snip...

No help with the real questions asked. :-(
Factoid:
My first job out of the Navy was with Ryan Stormscope company in Columbus, OH. I worked the receivers as they came off the production line, about 10-12 ladies hand stuffing boards. I also did the calibration. Calibration jig was a standard Stormscope antenna mounted on 12 inch legs placed over another antenna connected to the UUT. Calibration antenna was driven by an NE555. It placed a ring of dots on the display scope for the various range rings. Ten turn pots and small hand wound slug transformers on the receiver were adjusted for range and symmetry. All op-amps in the receiver. Memory storage was 256 bucket shift register, next hit in pushed the oldest data out and dot disappeared from the screen. As I recall when I left for another job they were just starting to look at designing in a Motorola 6500 processor. Interesting to watch the dots ripple across the screen as lightning strikes moved across the area.
Company at the time was like a small family owned grocery store. Good first 'real' job for me and I wonder where I would be today if I stayed.
Factoid end:
See I told you... Nothing added to the thread. :-0
Mike

 

[kruser]

My first job out of the Navy was with Ryan Stormscope company in Columbus, OH. I worked the receivers as they came off the production line, about 10-12 ladies hand stuffing boards. I also did the calibration. Calibration jig was a standard Stormscope antenna mounted on 12 inch legs placed over another antenna connected to the UUT. Calibration antenna was driven by an NE555. It placed a ring of dots on the display scope for the various range rings. Ten turn pots and small hand wound slug transformers on the receiver were adjusted for range and symmetry. All op-amps in the receiver. Memory storage was 256 bucket shift register, next hit in pushed the oldest data out and dot disappeared from the screen. As I recall when I left for another job they were just starting to look at designing in a Motorola 6500 processor. Interesting to watch the dots ripple across the screen as lightning strikes moved across the area.
Company at the time was like a small family owned grocery store. Good first 'real' job for me and I wonder where I would be today if I stayed.
Factoid end:
See I told you... Nothing added to the thread. :-0
Mike

All interesting info!!

I was given this Stormscope WX-110 when the club installed their first Thor Guard system.
The WX-110 was throwing an antenna error during it power on tests. I took the thing home and found the error appeared to be from a bad connection to the oblong antenna. Cleaned that up and never saw another error.

It's been ages since I've been inside the thing so I don't know if it used a Motorola processor yet or was just full of analog and other TTL and/or CMOS chips. I recall it was loaded with chips from the 1990 era and had at least two main boards if not three. I assume one was probably to handle the RF static signals from the antenna and then another (one or two boards) probably handled getting that onto the LCD display.
I never paid attention to any 10 turn pots or transformers but I probably just overlooked them.
I'd opened mine up as the EL backlight was failing and had turned mostly dark. I ordered some various "cut to size" EL sheets from eBay and was able to fit in a new EL backlight which worked fantastic and is still nice and bright to this day. The auto dimming circuit also still works which I assume was a feature they liked in the ATC towers.
This Stormscope would have came from a member of the country club that probably sold equipment for airports back in those days.

I have noticed mine has lost sensitivity along it's eastern most parts of the display when storms approach from the east (which is rather rare here). It will still display lightning coming from the east but not nearly as well as from the west. Luckily, our predominant storm direction is from the west, southwest so it still comes in very handy for my use.
Your mention of a calibration antenna using 555's makes me think it could just need a calibration but without any technical info on the electronics, trying to calibrate it would be mostly guess work. I suppose I could attempt to build some form of a test jig to simulate lightning crashes and use that attempt a calibration as long as I could figure out which pots and coils do which direction. That could be hard though as I don't recall anything being marked on the boards as to a controls function.

And yes, it's still fun watching the dots move across the screen as the storms move through!!
I'll say one thing. It has an amazingly accurate image made of dots that very closely resemble the NWS Doppler radar images as long as the approaching storms have electrical activity within them! Of course the antenna must be properly oriented which mine is.

If you recall any other technical details, please pass anything on, I'm all ears!

I do plan on opening mine up soon as it's all still original other than the EL backlight sheet. I figure there must be several dried up capacitors within mine that could stand being replaced.

Thanks for sharing your memories!

 

[kb5udf]

Not long ago I helped out a nearby park with some coverage issues. They were running Thor Guard, with their system operating in the 27mhz range. I recall it was being in the CB BAND. If memory serves the transmitting antenna to alert the remote sirens in the park looked like two hamstick type verticals arranged as an inverted-L. With a small tweak to a receive antenna location it worked fine, but the range of this transmitter was unimpressive.

Point is, don't be shocked if you don't here one of these things even a mile away.

 

[KE5MC]

All interesting info!!

I was given this Stormscope WX-110 when the club installed their first Thor Guard system.
The WX-110 was throwing an antenna error during it power on tests. I took the thing home and found the error appeared to be from a bad connection to the oblong antenna. Cleaned that up and never saw another error.

It's been ages since I've been inside the thing so I don't know if it used a Motorola processor yet or was just full of analog and other TTL and/or CMOS chips. I recall it was loaded with chips from the 1990 era and had at least two main boards if not three. I assume one was probably to handle the RF static signals from the antenna and then another (one or two boards) probably handled getting that onto the LCD display.
I never paid attention to any 10 turn pots or transformers but I probably just overlooked them.
I'd opened mine up as the EL backlight was failing and had turned mostly dark. I ordered some various "cut to size" EL sheets from eBay and was able to fit in a new EL backlight which worked fantastic and is still nice and bright to this day. The auto dimming circuit also still works which I assume was a feature they liked in the ATC towers.
This Stormscope would have came from a member of the country club that probably sold equipment for airports back in those days.

I have noticed mine has lost sensitivity along it's eastern most parts of the display when storms approach from the east (which is rather rare here). It will still display lightning coming from the east but not nearly as well as from the west. Luckily, our predominant storm direction is from the west, southwest so it still comes in very handy for my use.
Your mention of a calibration antenna using 555's makes me think it could just need a calibration but without any technical info on the electronics, trying to calibrate it would be mostly guess work. I suppose I could attempt to build some form of a test jig to simulate lightning crashes and use that attempt a calibration as long as I could figure out which pots and coils do which direction. That could be hard though as I don't recall anything being marked on the boards as to a controls function.

And yes, it's still fun watching the dots move across the screen as the storms move through!!
I'll say one thing. It has an amazingly accurate image made of dots that very closely resemble the NWS Doppler radar images as long as the approaching storms have electrical activity within them! Of course the antenna must be properly oriented which mine is.

If you recall any other technical details, please pass anything on, I'm all ears!

I do plan on opening mine up soon as it's all still original other than the EL backlight sheet. I figure there must be several dried up capacitors within mine that could stand being replaced.

Thanks for sharing your memories!

Picture included of the generation I worked on. What came after I left and company sold much different in appearance, but likely a lot of basic principles the same. Receiver was broadly tuned for 150kHz. Lighting strikes have a predictable signal strength until you get into super cell activity, but then you don't need an instrument to know what to avoid if in clear air. Directional antenna was a rectangular 3/8" thick ferrite material with a hole in the center. Two loops of wire forming a X - Y configuration exiting thru the hole to a connector. Second antenna was a common simple whip called a sense antenna. Sense antenna determined which opposing quadrant the received strike is in. For an aircraft installation we had to know what surfaces (top or bottom) antennas were too located on. I don't recall how we addressed various mounting issues, but it was important to get the incoming signal displayed relative to the nose of the aircraft. Signal display was always relative to aircraft with no input to adjust for true north. Signal strength established how far to display from the center of the CRT display. Yes, the display was a CRT about 10-12 inches long with the aircraft pictured in the center. Displayed information in a 360 degree picture.
Google search might be helpful for you unit. Looks like over the years there have been several iteration and hardware improvement. The WX-7 was brute force digital logic and nothing fancy. Well maybe in the power supply as I recall it had switching PS for the higher voltage needed for the CRT. That was my first experience with switching power supplies.
Underlying principle were simple and challenge was to bring it all together in a package you could put in a light aircraft. We once installed on a BAC-111 aircraft. Air speed stripped the mounting gasket out between the skin and bottom of antenna. I'm not sure what the followup to that was.