The inexpensively manufactured dipole adapter for the antennas works without problems in practice. My setup: dipole with the two longer antennas on the tripod directly connected to the USB stick. For my experiments, I screwed the two longer antennas (as shown below) onto the dipole adapter and connected its connection cable directly to the USB dongle. I performed the following steps without the included extension cable. Adjustments would also be necessary at this point for a transmitter. Note that these antennas are only intended for reception. The longer specimens are 23 to 100 cm long and cover the frequency range from VHF to UHF. The shorter antennas are 5 to 13 cm long and cover the frequency range from UHF to around 1.5 GHz. In addition to a tripod and a suction cup holder for the antennas, only a dipole T-piece is (unfortunately) included - but two pairs of extendable antennas of different lengths can be used. The "luxury version" was in the Elektor package. Such SDR USB sticks are available in several variants. The above representation was taken from an unofficial data sheet. Unfortunately, the Formosa-based manufacturer does not release sufficient information about the behavior of its chip. The USB module supplied by Elektor is a tuner manufactured by Rafael Micro with the designation R820T, the interior of which is shown schematically in the following circuit. Something like this is therefore also found in USB sticks based on the RTL2832. The IC RTL2832 itself has no integrated tuner that takes care of the restriction of the recorded frequency range. In the documentation, Elektor even advises not to process more than 2.4 MHz at the same time. A realistic bandwidth is therefore a restriction to a maximum of 2.8 MHz or a little less. So it is a radio in the sense of the word usage.Īccording to the documentation and the information in the datasheet, the chip can monitor a spectrum of up to 3.2 MHz in "real-time operation." Practical experience shows that when this bandwidth is used to the fullest, samples are lost. It is not possible to send with the module. The SDR kit described here is about reception. It can collect I/Q samples and send them directly to the host - a function that was intended by the chip manufacturer to decode FM radio. Rumors have it that a Linux kernel developer discovered that the RTL2832 IC manufactured by RealTek is more than just a classic DVB-T decoder. The story of this radio module system known from the RTL-SDR blog began, as so often, with a coincidence. In times of increasingly inexpensive DSPs and powerful microcontrollers, this is an all too sensible train of thought. The principle is that parts of the signal processing, which used to be done in hardware (electronic components) are done digitally in SDR.
The term SDR as an acronym for Software Defined Radio should not really need any further explanation today. The affordable RTL-SDR Kit is an experimental platform that enables SDR reception with practicable hardware. Other potential applications are general radio scanning, air traffic control, public safety radio, ADSB, ACARS, trunked radio, P25 digital voice, POCSAG, weather balloons, APRS, NOAA APT weather satellites, radio astronomy, meteor scatter monitoring etc.If you have taken an amateur radio exam in the course of the last few years, you likely have come across the topic of software defined radio (SDR) several times in documents. Thanks to the included mounts and extension cables it is possible to temporarily place the antenna outside for a better reception. You can use this kit either for terrestrial or satellite reception just by changing the orientation of the antenna. This device can receive frequencies from 500 kHz to 1.7 GHz and has up to 3.2 MHz of instantaneous bandwidth (2.4 MHz stable).
Moreover, there is a software switchable bias tee circuit, supplementary ESD protection, lower overall noise and built-in direct sampling for HF reception. RTL-SDR is an affordable dongle that can be used as a computer based radio scanner for receiving live radio signals in your area. This particular dongle includes a R820T2 tuner, a 1 PPM temperature compensated oscillator (TCXO), SMA F connector. It features an aluminium case with passive cooling via a thermal pad.