One for the radio hams

[Brigand]

One for the radio hams I'd have thought.

Part of my job requires me using a bit of kit to scan across the frequency ranges listening for things, the kit works from around 10kHz to 3GHz, and you can hear all sorts of things.

I'm wondering if there is a website or similar out there that says what bit of kit makes a certain noise.

For instance, submariners listening to ships on their sonar sets could identify what type of ship and how fast it was going by the noises it was making.

Is there something similar out there that shows what a router sounds like for example, or any other item?

I have a diagram that shows what kit operates in a certain frequency range, just not specific sounds.

I'm just curious to know what makes all that noise!

[Krikkit]

Good start on the various bits and pieces: http://en.wikipedia.org/wiki/Radio_spectrum


Another good one for a browse (huge 5kx3k image warning): http://www.towercommservices.com/images/United_Sta...
It's for the US, but a lot of it is universal.

And finally the OFCOM listing, not completely exhaustive, but as close as you can get: http://www.ofcom.org.uk/static/archive/ra/publicat...

[Le TVR]

What it sounds like will depend on what demodulation mode you are using to listen.

Signals will totally different on an AM receiver to a FM receiver.
Then you can have sideband, NBFM etc etc...

[tank slapper]

I assume you want to identify various digital modes. There are a huge number, and although some are very distinctive (like ALE), others sound very similar (loads of different RTTY versions). In practice it is a case of combining what it sounds like with what else you know - like what frequency it is operating on, where it is transmitting from and its operating schedule. If you want to decode them, there is quite a lot of amateur radio software that can handle a variety of digital modes. There is software that attempts to classify transmissions, but it really isn't cheap - something like Hoka Code 300 is not far off £5k. Stuff that is encrypted you won't have a chance at decoding unless you happen to work at GCHQ, but then I doubt you would be asking here.

HF and shortwave probably has the largest variety - up to 30MHz or so, there are a great many stations using everything from morse to STANAG-4285. Above that, it tends to be a bit easier since people use fixed licensed frequencies and you can look up who is allocated what.

What radio are you going to be using to do this? I would suggest using a decent software defined receiver, or a panadaptor for the IF stage of the receiver you are using since it allows you to see portions of spectrum on a waterfall and effectively monitor more than one frequency. It can make it easier to spot brief transmissions and each transmission type tends to look distinctive.

Here are some pages with examples of various digital modes. Many of them are amateur modes, but there are some commercial and military ones there too:

http://www.hfradio.org.uk/html/digital_modes.html
http://www.kb9ukd.com/digital/
http://www.nonstopsystems.com/radio/radio-sounds.h...
http://wb8nut.com/digital/

[Brigand]

Thanks guys for some useful info.

Tankslapper, you hit the nail on the head with the second link you have, that's the sort of thing I'm looking for.

I use an Oscor 5000e, not a radio set per-se, its certainly not able to TX, but it's designed to scan the spectrum and look for covert eavesdropping devices. It has the ability to change between AM / FM modulation, listen to USB's and LSB's, plus much more.

I was just curious as to what the nature of a lot of the sounds I hear when playing with that set are.

I appreciate the pointers!

[tank slapper]

Brigand said:

I use an Oscor 5000e

Now that is an interesting piece of kit. Want.

[Brigand]

tank slapper said:

Now that is an interesting piece of kit.

That it is!