such ghost stations. Most of them seem to broadcast only numbers.

Google "ghost radio stations". Quite interesting. There seems to be one in Nebraska that plays easy listening classics 24/7.

And they seem to go back to the early days of radio.

There's a station that just broadcasts someone reading numbers out loud, some with just tones or such.

Not a way out there thinker myself but it can be theorized as just about anything from a place to listen for orders or information in time of conflict or war to a signal at a frequency that keeps that frequency out of other hands.

It could mean anything.

Weird though that's for sure, because someone has to maintain the equipment and someone created it in the first place for a reason.

Always have been. As a kid, I was an avid short wave listener and often tuned around the shortwave bands. I heard a lot of number stations in various languages, weird stations broadcasting tones, and other stuff. It was puzzling back then, and such stations are still puzzling.

However, a lot of the mystery is gone these days. Some of the weird sounds I heard broadcast actually transmit data of some sort. Most are well-known. The number stations, where someone reads blocks of four or five-digit numbers? Most of those are military in nature, and use a fairly primitive form of encryption to send messages. Why they're still around, though, nobody knows. Most of that simple encryption was broken long ago by the NSA and equivalent agencies around the world. Sometimes, it's just radar plotting data being transmitted from one place to another. Other times it's something else, but it's not all that secret anymore.

It's still fascinating to scan through all of the frequency bands and try to figure out what the strange signals are doing. Now, with Software Defined Radio (SDR) systems available for under $20 that use a USB dongle plugged into your PC and software that lets you scan frequencies from 100 khz to 2-3 ghz, with a spectrum analyzer display on your monitor, you can look at lots lots more stuff than ever before and actually see what the signal looks like on a constantly updated display that appears under the spectrum analysis screen.

$20! Equipment that could do all that used to cost up into the 6 figures, but now, it's available on Amazon, eBay and just about everywhere, with the software platforms free for downloading.

I have one of those SDR USB things plugged in and spend some off time looking around to see what's out there. It's interesting. Add-ons to the free software will let you decode all sorts of things, from NOAA weather images to digital TV signals and much, much more. It's fairly technical stuff, but not that difficult to use, once you understand the basic language of SIGINT. What you can see and receive depends on your antenna, and decoding some stuff requires a specialized antenna and maybe a couple of other bits of hardware, but just the USB dongle and the free software will turn your PC into an amazing radio frequency scanner with a display that shows you more than people could ever see before.

A warning, though: This stuff is highly addictive. It can suck you right in and take up huge amounts of your time. Today, you can have a very capable SIGINT console sitting on your desk for around $20. There's an almost unlimited number of signals you can receive, and lots of websites showing you how to make sense of them and decode them to do a lot of stuff you'd never think was possible.

Fun Times! What used to cost upwards of several hundred thousand dollars, or even millions in some cases, is now available for $20! Amazing.

Want to learn more about all this: Go to this website, which will give you tons of information on Software Defined Radio and what you can do with it. Remember: It only costs $20 or less to get started.

http://www.rtl-sdr.com/

Google SDR to find an overwhelming amount of information. I'm having a ball for my $20. It all takes me back to my old USAF days.

Fun.

a realm I've never much thought about. Interesting stuff. Thanks for sharing!

I just bought the dongle as well as an adapter so I can screw it into my ham radio mag-mount antenna.

with the dongle:

You can download the software here: http://airspy.com/download/
Download the first package: Windows SDR Software Package. The 64-bit one didn't work on my Windows 10 machine. It's a manual install. Instructions below. If you follow them exactly, everything will work out just fine.

Installation of the software is a bit fiddly. Instructions here work just fine:
http://www.rtl-sdr.com/rtl-sdr-quick-start-guide/

I hope my machine can handle it. It's Windows 7,and a couple of years old. It's a rebuilt one from my job. I had the guy put in a SSD and plenty of RAM, but it wasn't anything particularly high powered initially.

I'm by an airport, I'm near NYC, and it's plenty busy around here!

Having plenty of RAM is important. A lot of people are using the software on Windows 7.

Right now, I'm tuned to one of the arrivals frequencies for MSP airport here. You can find frequencies for any airport on Google, and the software lets you set up presets for frequencies, with labels, to help you return to them. I'm just using a short telescoping whip antenna in my basement, of all things. I may upgrade to a broadband antenna outdoors, though.

I've been exploring other bands, as well. The software can decode the most common transmissions, and add-ons are available for many other broadcasts, including digital voice, but it's pretty technical getting those set up and I haven't done that yet. there's a scanner add-on, as well, but I haven't tried that, either.

Have fun!

Ham and FRS/GMRS radios have privacy tones that squelch incoming signals that don't have the tone... helps keep interference down.

Does the software also show that stuff?

those radios, using Narrow FM (NFM). There are a lot of them in the 450-460 MHz band around here, mostly used in the construction industry. Pretty boring most of the time, really. During hunting season, there are also a lot of them in use, but not close enough to me to receive them.

There are tons of non-voice and digital signals everywhere. I haven't gotten involved in those so far, but there is decoding software for almost everything that runs as an add-on to SDR#. A lot of is is developed by individuals, though, and not much help is available for installation and configuration.

I'll probably start investigating that next, starting with the digital voice stuff used by police and fire depts. When they switched to digital, my scanner was pretty much rendered obsolete, so I'm looking forward to experimenting. If you have two of those dongles, you can even handle trunked signals.

There is an unlimited number of ways this technology can be tweaked and there are people tweaking it all over the place. You can even do amateur radio astronomy with those dongles. Amazing!

If you have privacy codes turned off on your receiver, you'll hear everything on that channel. But if you want to transmit to somebody using the privacy codes, you need to know what it is or their radio will squelch you because you don't have the right code.

And I do kinda want to listen to what the local airport VOR sounds like.

Dear god, this could be addictive. Much easier programming on a computer than trying to program a scanner, with its little digital display.

Being able to see active signals in the spectrum and being able to see something about what they contain in the "waterfall" display below makes you want to look more closely. By the way, there's a slider on the right side of the interface that lets you zoom in on part of the spectrum or zoom out. You can tune by clicking on any of the numbers in a frequency. If you click at the top of a number, it increments up by one. Click on the bottom of the number and it increments down. That's now how we're used to tuning, but it makes a huge amount of sense, and is precise.

There's no written manual for the software, so you sort of have to figure it out, or get on one of the forums that talks about this stuff and ask questions. You'll get used to what decoding you need from the signal's appearance, as well. Sideband transmissions are easy to recognize, as are AM and FM. For frequency shift modulation (FSM), you can see that happening on the screen if you zoom in, too.

There are lots of signals that are useless at the beginning, since you can't decode them, but decoders are available for many, many types. Most are being written by some guy in Russia, though, and I'm a little leery of downloading them.

This is all pretty new stuff, so there will be more and more capabilities to decode more and more signal types as time passes. It's pretty exciting stuff, I think, and I don't even have a good antenna. That's the next thing on my list - a broadband UHF antenna on my roof. Just don't tell my wife!

...well, that's a VHF and UHF antenna. Directional, too.

You can pick up a motorized rotator for it so you can point it in the direction you want. Used to be common back before cable TV.

When I was a kid we had a Radio Shack one for our rooftop TV antenna. I used to pretend it was a radar screen. Drove my mom nuts...

discone antennas like the one below are the hot item for these systems. They're not directional and cover 300 mhz to 3 ghz. I do fine with a whip antenna for the lower frequencies, but I'm thinking about one of these for the other end of the spectrum. YOu can find cheaper ones on eBay, too: About $50 or so.

But I have my mag-mount antenna for my ham radio. I'll use that for now.

I'm currently using the telescopic whip. It's sitting on the top of an unused PC near my desk in a basement. That's it, and I'm getting all of the airport signals from about 10 miles away, along with many hundreds of other signals in all bands.

In a basement. I can't imagine what will happen when I get a decent antenna mounted outside. I suspect it will make me slightly crazy, trying to figure it all out.

I think it's worth $50 to set something up outdoors. For now, though, I'm having plenty of fun with the stuff that came with the dongle.

You can click on the spectrum display or on the waterfall history display to tune to a signal. For intermittent signals, it's easy to click on the last transmission in the waterfall and be sure you're locked onto that frequency when the next transmission begins. It took me an hour or two to figure that out.

You can also click and drag left or right in the waterfall to move up and down the spectrum. You can also adjust how much of the screen each part uses by dragging the border between them. Also, mess with the sliders on the right to change how the display looks and find a balance you like. The program remembers your settings and starts up with everything set as it was when you shut down.

There are still other things I haven't completely figured out yet, I'm sure. You can't hurt anything by fooling around with the interface, so experiment as much as you like. It's a pretty cool piece of software, really.

I just wanted my own personal toy.

of fun! Oops!!! Look what I just found, a Linux SDR!!!

Gqrx is an open source software defined radio receiver (SDR) powered by the GNU Radio and the Qt graphical toolkit.

http://gqrx.dk/

WOW!!!

Let me know what you come up with.

it on eBay, once I found out that the particular model I had was very popular. I bought mine at a garage sale for $5. It sold on eBay for over $300. Who knew?

I've had a lot of different SW and VHF radios during my lifetime, including a Knight Kit from Allied Radio that I put together when I was 12. This new SDR stuff is the coolest thing I've found yet. I used to sit at a console while in the USAF that had a frequency spectrum display, but that console cost the government half a million dollars. Now, I have the equivalent for $20. You've gotta love technology!

It's a toy, of course, but what a cool toy!

Allied Radio, I used to order all the time from Allied Radio way back. I loved getting their catalog and pouring over it, ha, looking at things I could never afford. I had a National NC-125 I used for years on a really long, long-wire antenna. This SDR stuff is interesting. I was glad I saw your post. It had crossed my mind before, but I never dreamed one could get into it so cheaply now. Thanks!!!

that its lower frequency limit is about 25 MHz. You can buy an inexpensive up-converter, though, that handles lower frequencies. I'm more interested in the VHF and UHF bands, though, so I haven't sprung for that device yet. The shortwave bands aren't as interesting as they once were, though, I think. Most countries have dropped their SW broadcasts, opting for the Internet, instead. Ham bands are not as interesting any longer for me, either. VHF and UHF have tons of interesting stuff going on, though.

I got spoiled while in the USAF, since we got to play with state-of-the-art stuff. It kind of spoiled me for normal receivers. But, now, that high-tech is easy to get and very affordable. I'm loving it, and will probably explore it even further.

I think just about all countries have dropped beaming to North America. I really haven't heard much for amateurs anymore on the lower frequencies. Maybe it's more popular in other areas.

Havana is beaming a lot into the US. I listen to their English broadcast sometimes at night. It's quite interesting. I've also heard some Chinese and Vietnam stations that relay here. I get about 10 international stations mostly from Cuba and Mexico I guess. They are in Spanish which I can't understand.

I wonder what a good antenna would be for VHF and UHF? I have these HOA restrictions on antennas, but I could locate one on the back of the house, I think, with none noticing. The discone antenna you posted looks interesting if not too expensive?

a really simple antenna might just work fine. Here's the SDR dongle I bought:

https://www.amazon.com/gp/product/B01GDN1T4S/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

It came with three antennas. I'm using the telescopic one. I have it inside in my basement, and I'm getting a really wide range of signals. But, I live in the Twin Cities of MN, so there's lots going on around here. I may upgrade to a better antenna, but for now, thise one is pulling in plenty of stuff to look at.

These things are surprisingly sensitive and VHF/UHF are pretty much line-of-sight, anyhow.

try something like this, but it the past it looked prohibitively expensive just to try. I will definitely do this sometime soon. This looks like a lot of fun! Thanks for the link MM!!!!

1950's and 1960's

Loran-C (there's a sound sample)

Loran

When I was growing up in the 1960's - my father loaned me his Hallicrafters SX-100 - and I would listen to all so sorts of stations.

There were several sounds similar to the Russian transmission.

I pointed these out to my father - they turned out to all be local - usually direction finding signals - for ships in the Gulf of Mexico - or for planes landing at the local airports.

Nowadays GPS has replaced most (if not all) of these - but it's conceivable that Russia may still have similar signals in use.

There's something about actual voices and sounds out of the ether that fires the imagination.

during the early 1960s. They were told it was a VLF Naval radio station for communicating with submarines but he always felt that there was more going on there than what they were told.

It wouldn't shock me if this station has a similar role to Cutler.

ot just a general wide area code transmission station.

"Give me channel 83, Max."

to tune in to this freq for instructions?

That's what I've often thought too, emergency broadcast. There must be some reason they keep it online.

http://websdr.ewi.utwente.nl:8901/

are being sent now.

Now...........you prove me wrong on this????... .............here is the scoop................................

There are millions and millions of stars...So..are we the only one with planets?
........and of those hundreds of thousands with planets..(probably millions)..are we the only ones with life..?
............................only ones with..so called "intelligent life?".........now grasp this one for a moment......
............................so there are hundreds of planets...out of the hundreds of thousands of planets out there...
...............of those hundreds of planets with intelligent life. Are we the only planet that has advanced this far?



Thank you for reading this if you have gotten this far...no one knows how much intelligent life is out there..If they are really smart, they would avoid this nut farm...My guess is they already have............

Along with some others at the link

This is really a great summary!!! Thanks!!!