User Tools

Site Tools


Welcome to the wiki!

This Wiki is intended to collect all sorts of disparate information concerning the use of the so called RTLSDR. If you wish to add to this wiki please contact the Osmocom guys and ask for editing access rights to this site.


The Chips

  • RTL2382U - The ADC and USB data pump. It is mated with one of the following three tuner chips. NDA needed for the data sheet.
  • E4000 - Tuner. 60MHz to 1700MHz The Elonics E4000 is the most desirable tuner to have as it's the most capable. This part may now be in short supply as Elonics IP seems to be up for sale. NDA needed for the data sheet.
  • FC0012 - Tuner 50MHz to 1000MHz ; Fitipower - no public information available.
  • FC0013 - Tuner 50MHz to 1700MHz ; Fitipower - no public information available.
  • R820T - Tuner 24MHz to 1850MHz ; Now the E4000 has gone this is the tuner to get as it's comparable in performance. It also seems to be cheaper overall.


What to listen to

By installing and using RTLSDR hardware and software you have now entered the long established world of scanning and receive only HAM radio. The twist is that instead of using expensive purpose built hardware you are using a PC (which you no doubt already own) and a $20 USB dongle. It is now possible to listen to:

  • FM: both narrow band and wideband. The former is used on two way radio systems such as emergency services and private radio networks (like couriers and taxis) and UHF CB and the latter is the usual broadcast FM the likes of which you have in the kitchen and car. Aircraft and boats and ships also use narrow band FM which you can use RTLSDR to listen to. The SDR# software can receive both narrowband and wideband FM and the latter do stereo FM too!
  • AM: Most AM transmissions are below the bottom frequency of RTLSDR dongles. You will need a translator (I'll deal with translators soon) to get these frequency bands.
  • Upper/Lower Sideband (USB/LSB). See AM above.
  • CW: Continuous wave for morse code enthusiasts.
  • With GNURadio you can receive and demodulate digital modes such as pagers (POCSAG), ADS-B (aircraft positions), AIS (ship positions), AP25 and TETRA (digital trunk radio) and many others.
  • GPS reception is currently being worked on but should be do-able.
  • Satellite reception including receiving ham transmissions from the International Space Station are possible to. I have seen some screen shots of someone using RTLSDR and a 2.5m dish to track the carrier signal on deep space robots such as Voyager and the Mars missions.
  • This post alludes to the tuner chip being disabled and the RTL chip being used to receive transmissions at 30MHz and below.


  • IRC: On Freenode join the very active channel ##rtlsdr (make sure it's two #'s.)
  • Google Groups: Search for and join in the group “ultra-cheap-sdr”
  • RTLSDR on Reddit

History and Discovery of RTLSDR

It turns out that Antti Palosaari is perhaps not entirely responsible alone in getting credit for the discovery of Realtek 2832U tuners being used for SDR. The RTL2382U parts were always intended by design for SDR as the dongles come with closed SDR software in Windows for DAB+ and FM reception on the mini CD. I think the credit for uncovering of what the Windows software does lies with a fellow named Eric Fry originally sniffing the USB packets from the Windows application in FM and DAB mode way back in March of 2010. He had hoped to get a DAB+ or FM receiver working in Linux (he had originally been providing unofficial support for Linux and this Quad Realtek DVB tuner). Eric and I discussed this privately at length and I made some reflections about this SDR feature in 2011 on the linux-tv mailing lists and discussed SDR potential on the associated #linux-tv IRC channel. Realtek had sent me some alpha FM SDR software for Linux with a promise of DAB+ to come. Antti's infamous email followed in early 2012. Very quickly the Realtek RTL2382U Linux driver and and some independent work by Osmocom (who were making their own E4000 based SDR) collided and in RTL-SDR as we know it exploded onto the scene.

So, the original 'discovery' lies with Eric. Much of the work getting the RTL2382U and it's associated tuners tamed in between then and now lies with Antti and Osmocom.

start.txt · Last modified: 2013/11/10 21:44 by roklobsta