CW (Morse Code) with RTL-SDR
YouTube user Wolfgang Bleher shows in this video his reception and decoding of Morse code using an R820T RTL-SDR stick, HDSDR and CWSkimmer. He used a 2m Yagi as the antenna.
Category: HF
Tip: Effect of Power Sources on the Ham It Up Upconverter
The Ham-It-Up upconverter uses a 5V USB power input. I discovered that different 5v power sources can cause significant interference with this upconverter, and the same effect will probably occur in other upconverters as well.
When the upconverter was powered by mains power via a phone charger, the signals were almost completely drowned out in noise. Powering it with a PC USB port was better, but the PC USB power introduced some other strong noise sources. Powering it with a battery (used a mobile phone with OTG cable) was the best option. There are still some strong noise sources present, but I can probably solve them with better shielding.
Click continue reading to see some comparison images.
Receiving SSTV with RTL-SDR
Over on the Radio Antics blog fellow RTL-SDR enthusiast Andrew has been using the RTL-SDR to receive Slow Scan Television (SSTV) amateur signals. SSTV is a method ham radio enthusiasts use to send small images to one another. The images often contain their ham call sign overlaid on the image.
Andrew was able to receive several SSTV images using an R820T dongle tuned to the 27 MHz (11 meter) band. He also used a Funcube Dongle+ and got similar results.
Check out his post for some of the images he received, and his video below for an example of the receiving process.
STANAG 4285 Decoding with RTL-SDR
In this video YouTube user Superphish shows decoding of the French Navy STANAG 4285 test signal. He used an rtl-sdr, Ham-it-up upconverter, SDRSharp and a decoding program called Sorcerer. Watch in HD to read the text, though the text basically just repeats the French equivalent to the quick brown fox, “VOYEZ VOUS LE BRICK GEANT QUE J EXAMINE PRES DU GRAND WHARF” and some test symbols over and over.
Fair warning with the Sorcerer download: Some people report that their virus scanner detects a trojan on some Sorcerer download links. The Sorcerer link above seems to be clean though, as far as my virus scanner reports. An alternative decoder is Sigmira.
STANAG 4285 is the NATO standard for HF communication, and signals can be found all over the HF spectrum.
Integrated RTL-SDR HF Upconverter
Over at KF7LZE’s Blog a post about an upcoming integrated HF upconverter using tiny surface mount components has been posted. It is made by Marty KN0CK and will be for sale on KF7LZE’s site soon.
Marty KN0CK developed a very interesting v1.0 HF converter based on surface mount technology that fits inside the casing of an RTLSDR tuner dongle. He’s recently sent me schematics for the revision, which should offer even better performance.
RTL-SDR Direct Sampling Compared with WebSDR
YouTube user opilarczyk has posted a video comparing HF performance of the rtl-sdr with the direct sampling mod at 7MHz with WebSDR, an online SDR streaming site. The comparison shows how the direct sampling mod is extremely susceptible to broadcast FM interference.
RTL-SDR Receiving Sporadic-E
YouTube user tvdxrools . has posted a video showing the performance of the rtl-sdr dongle on receiving sporadic-e. Sporadic-e is a phenomenon which can allow signals of frequency up to 150MHz to travel much further than they could usually. More information about sporadic-e can be found here.
RTL-SDR at 80m with Homemade VEE Antenna and Butterworth Filter
YouTube user VoiceOfShortWave has posted a video of his rtl-sdr dongle receiving HF LSB ham radio transmissions at 3.7MHz with excellent performance. He used a homemade VEE antenna, and also a Butterworth filter to help reduce FM band interference. His other video shows the effect of his butterworth filter with 60MHz cutoff turning on.
