aunumero73 Over on YouTube has posted a video illustrating the difference in FM Selectivity on the FunCube Dongle Pro+ and a R820T tuner based RTL-SDR. The FunCube Dongle has an expected performance advantage over the RTL-SDR but one must consider the price difference ($190 vs ~$20) between these two devices.
If you’re looking for a dongle to use as an RTL-SDR, check our page on where to buy rtlsdr tuners.
“I wrote a octave wrapper around the rtl-sdr library of osmocon. With a little change, to also export the rtlsdr_i2c_read/write_reg function as well as the rtlsdr_set_i2c_repeater function. I then let the standard library do its normal work and just before measuring, I overwrite the E4K_REG_BIAS, E4K_REG_SYNTH1 and E4K_REG_FILT1 registers to their appropriate settings.
Raw data is available. The image itself is pretty raw. The only modifications are a shift of 3 dB below 350 MHz, to compensate the loss due to for 3-phase mixing. and a moving average of 10 samples, to smoothen the curve a little.” — kirepudsje
Kevin Mehall has posted some python source code that is capable of accessing rtlsdr / GNU Radio samples directly.
“This script decodes the packets that Oregon Scientific remote thermometers (like the one pictured [above]) send to the display unit. It also serves as example code for accessing rtl-sdr / GNU Radio samples live from Python.
Each sensor transmits every 30 seconds on 433.9MHz. The packet is repeated twice. Modulation is On-off keying, and the 32 data bits are manchester encoded. “ — kevinmehall
“This is a simple demonstration showing how one can receive HF using the ultra-cheap RTL2832U-based DVB-T USB dongle and a transverter (to move the HF signals into the range that the tuner in the dongle can receive).” — Balint256
“This time small “side by side” comparison of a Funcube dongle and a cheap RTL SDR DVB-T dongle (Hama Nano) connected to the same antenna with no preamp and using identical test signals from geostationary UHF military satellite downlinks in the 240 – 270 MHz range to compare received signal to noise ratios (SNR).
The FCD is used “live” in this video while the DVB-T IQ stream (1MHz bandwith) was prerecorded a few minutes before the video in order to avoid having to switch the dongles and reconfigure software back and forth and thus save some time in the video…
Most of this satellite downlinks are encrypted data links except for the illegal Pirates from Brazil or occasionally other unintended uplinks or harmonics making it into the uplink :-)” – MegaOscarVideos
“A small “side by side” comparison of a Funcube dongle and a cheap RTL SDR DVB-T dongle (Hama Nano) connected to the same antenna and using identical test systems from a geostationary INMARSAT satellite to compare received signal to noise ratios (SNR).
The FCD is used “live” in this video while the DVB-T IQ stream (1MHz bandwith) was prerecorded a few minutes before the video in order to avoid having to switch the dongles and reconfigure software back and forth and thus save some time in the video…” –Ottiki
The MachineGeek overt at DangerousPrototypes has posted yet another great update on a RTL-SDR project.
Balint Seeber has done it again! In this video he shows how to take the RTL-SDR dongle and use it in conjunction with the open source OP25 project to successfully demodulate APCO Project 25 (P25) digital radio voice communications. P25 is a term used to refer to a modulation system used by many public safety agencies for digital radio transmission purposes.