Software-defined radio, or SDR short (Software Defined Radio) is a radio communication system in which the usual hardware components (such as mixers, filters, amplifiers, modulators / demodulators, detectors, etc.) created by PC software or firmware embedded in system. This is not a game-changing technology. The first mention can be found at the end of the seventies, when Walter Tuttlebee described the concept of VLF radio, utilizing A / D converter and microprocessor Intel 8085th Furthermore followed SpeakeEasy project, focusing on the U.S. defense system. His aim was to use digital signal processing, and range from 2 to 2,000 MHz replace up to ten existing military radios. The historical sequence we must not forget also, the year 1991 when Joseph MITOL created and a year later published extensive work on the subject, designed for a wide field of technology. More information on the historical development of SDR receivers can be found on the Internet.
Today the situation is much better than it was in the early days of his birth. Since the SDR receiver typically consists of several functional units separately, it is possible to create a variety of different approaches. From the highest when the input filter placed in one or more of fast A / D converter, followed by a configurable gate array (FPGA), taking care of the basic signal processing to the simpler designed especially amateur construction. They are used to digitize the signal usually Line-In input of your sound card (see block diagram in Figure 2). Sampling frequency is equal to the received range yet. Ie. when you use a sound card with a sampling frequency such as 192 kHz is also available software tunable range of 192 kHz. Greater extent then provides for the exchange of crystals in the receiver or tunable oscillator (VCO).
Receiver SDR-5+ HF
SDR-5+ is a powerful, easy to use SDR receiver "Software Defined Radio", for connection to PC. Its foundation is the only modern component base, which is the source of unrivaled excellence and parameters.
For ease of use is part of the receiver integrated generator - VCO. Frequency range can be set in the range from 800 kHz up to 45 MHz. Frequency stability is yet better than ±40ppm/°C and guarantees good reception. To the extent the generator is not enough, you can use an external BNC input generator with a frequency of up to 100MHz!
The antenna is the SDR-5+ connect using two different connectors. Unbalanced BNC connector is used to connect a coaxial cable with characteristic impedance of 50 ohms. In contrast, two 2 mm connectors are used for connecting eg LW antenna with an impedance of 450 ohms. The two antenna inputs are separated.
The main and decisive element in each receiver are always good frequency filter and low noise amplifier. Therefore, the receiver SDR-5+ includes a total of four filters and two low-noise amplifier with gain 2 x 20dB.
Output I / Q signals are connected via 3.5 mm stereo jack ready to connect to the Line-In input of your sound card and any further decoding and listening to old software. The advantage is that it is a diagram useful in a very wide frequency range and their properties rivaling professional receivers.
Using a receiver SDR-5+ HF
Using receiver SDR-5+ is very simple and at the same time universal, which is based on wide frequency range. SDR-5+ can be used practically to receive all services in long, medium and short waves AM, NFM, WFM, LSB, USB, DSB, CW and CW-L-U modulation. In addition to radio stations can also receive amateur radio broadcasts, synoptic maps, military installations, submarines, navigation beacons, and much more.
Example of use (frequency in kHz):
Installing the receiver
Receiver SDR-5+ are supported by all standard SDR software. Among the most common are: WINSDR, HDSDR or a new open source SDR# (SDR Sharp). Since this is a very interesting project, which is for non-commercial use completely free of charge, we describe the use of SDR-5+ along with the SDR#.
Application does not need to install, just download and unzip the following address:
After unpacking the software SDR# ready to use! It is not necessary to install anything!
The first use of the
After unpacking SDR # files can immediately start the application SDRSharp.exe that after reading the following window:
For starters, you can try such as receiver for receiving the classic AM radio broadcast:
1) First, connect the antenna to
the receiver, power supply (12V DC) and 3.5 jack to connect the
Line-In input of the sound card
2) Next, run the application SDRSharp.exe
3) Set the recording from line-in (no microphone)
4) In addition to the Play button to select "Other (Sound Card)"
5) Select the type of modulation
6) Click the play button
7) Adjust the frequency of the VCO
8) Section Frequency finely adjust the reception frequency
9) If everything works as it should, it should show the received spectrum from PC speaker should hear noise or music
Of course SDR # is not the only application that supports modules SDR-5 +. Among the most common is that, inter alia also WINSDR or HDSDR and many others.
Receiver SDR-5 + are now available through both trade eBay Store and through our e-shop. I also have a switched adapters and other accessories. For more information visit: http://stores.ebay.com/pandatroncz
Odkazy & Download:
SDR-5+ HF receiver - All Mode Software Radio - SDR-5+ HF receiver - All Mode Softwarový přijímač (only for Czech Republic)
SDR receiver - The module PSDR - PSDR - SDR přijímač, modul (only for Czech Republic)
PGEN45 - Generator 8 kHz to 45 MHz - PGEN45 - Generátor 8 kHz až 45 MHz (only for Czech Republic)
Software SDR Sharp