[LINK] Software Defined Radio

[Stephen Loosley]

RTL-SDR

For the uninitiated, someone figured out that if you take a $2 USB tuner designed to pick up digital TV broadcasts, you can also use it to listen to ... virtually everything else in the radio spectrum. Pilots chatting to air traffic control, mall security, local emergency services, ham radio, meteors and radio astronomy (the sound of magnetic storms on Jupiter, anyone?), shortwave music stations from the other side of the planet, downloading live pictures from weather satellites passing across your rooftop, tracking ships at sea, the list goes on and on and on.

All this without any kind of Internet connection - if I were off grid this would keep me busy forever.

It should really be called "how to do almost anything in software defined radio on a budget"

If you want to know more, start here! This has everything you need to know: http://www.rtl-sdr.com

For example: (Quote)

What is RTL-SDR?

RTL-SDR is a very cheap Software Defined Radio that uses a DVB-T TV tuner dongle based on the RTL2832U chipset. With the combined efforts of Antti Palosaari, Eric Fry and Osmocom it was found that the signal I/Q data could be accessed directly, which allowed the DVB-T TV tuner to be converted into a wideband software defined radio via a new software driver.

Essentially, this means that a cheap $20 TV tuner USB dongle with the RTL2832U chip can be used as a computer based radio scanner. This sort of scanner capability would have cost hundreds or even thousands of dollars just a few years ago. The RTL-SDR is also often referred to as RTL2832U, DVB-T SDR, RTL dongle or the “$20 Software Defined Radio”.

There are many other software defined radios that are better than the RTL-SDR, but they all come at a higher price.

Currently we think that the Airspy ($199) and SDRPlay ($149) SDR’s are the best low cost RX only SDR’s. Then there are the HackRF ($300USD) and BladeRF SDRs ($420 and $650), which can both transmit and receive.

What is Software Defined Radio?

Radio components such as modulators, demodulators and tuners are traditionally implemented in hardware components. The advent of modern computing allows most of these traditionally hardware based components to be implemented into software instead. Hence, the term software defined radio. This enables easy signal processing and thus cheap wide band scanner radios to be produced.

What are some RTL-SDR Radio Scanner Applications?

The RTL-SDR can be used as a wide band radio scanner. Applications include:

    Listening to unencrypted Police/Ambulance/Fire/EMS conversations.
    Listening to aircraft traffic control conversations.
    Tracking aircraft positions like a radar with ADSB decoding.
    Decoding aircraft ACARS short messages.
    Scanning trunking radio conversations.
    Decoding unencrypted digital voice transmissions.
    Tracking maritime boat positions like a radar with AIS decoding.
    Decoding POCSAG/FLEX pager traffic.
    Scanning for cordless phones and baby monitors.
    Tracking and receiving meteorological agency launched weather balloon data.
    Tracking your own self launched high altitude balloon for payload recovery.
    Receiving wireless temperature sensors and wireless power meter sensors.
    Listening to VHF amateur radio.
    Decoding ham radio APRS packets.
    Watching analogue broadcast TV.
    Sniffing GSM signals.
    Using rtl-sdr on your Android device as a portable radio scanner.
    Receiving GPS signals and decoding them.
    Using rtl-sdr as a spectrum analyzer.
    Receiving NOAA weather satellite images.
    Listening to satellites and the ISS.
    Radio astronomy.
    Monitoring meteor scatter.
    Listening to FM radio, and decoding RDS information.
    Listening to DAB broadcast radio.
    Use rtl-sdr as a panadapter for your traditional hardware radio.
    Decoding taxi mobile data terminal signals.
    Use rtl-sdr as a high quality entropy source for random number generation.
    Use rtl-sdr as a noise figure indicator.
    Reverse engineering unknown protocols.
    Triangulating the source of a signal.
    Searching for RF noise sources.
    Characterizing RF filters and measuring antenna SWR.

Furthermore, with an upconverter or direct sampling mod to receive HF signals the applications are expanded to:

    Listening to amateur radio hams on SSB with LSB/USB modulation.
    Decoding digital amateur radio ham communications such as CW/PSK/RTTY/SSTV.
    Receiving HF weatherfax.
    Receiving digital radio monodial shortwave radio (DRM).
    Listening to international shortwave radio.
    Looking for RADAR signals like over the horizon (OTH) radar, and HAARP signals.

Note that not all the applications listed may be legal in your country. Please be responsible.


PS: The following sites are an excellent start:

http://www.rtl-sdr.com/rtl-sdr-quick-start-guide

And …

https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Telescopic/dp/B011HVUEME/ref=sr_1_1?s=electronics&ie=UTF8&qid=1500042787&sr=1-1&keywords=RTL2832U

Or:

http://www.trademe.co.nz/Browse/Listing.aspx?id=1371219488

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Cheers,
Stephen