Questions tagged [software-defined-radio]
Radio devices that use digital signal processing in place of analog electronic components to manipulate RF signals.
190
questions
5
votes
3answers
136 views
ARRL handbook as a reference for all your radio learning needs?
Looking to take up learning understanding everything from basic electronics to how today's wideband radios work, so that I can build my own radio systems (not just ham radios), and talk radio concepts ...
2
votes
0answers
33 views
Demodulating ISO14443 (part of NFC) using SDR?
I'm looking for info on demodulating both sides of an ISO14443 communication using a cheap SDR, preferably an RTL-SDR (R820T2+RTL2832U). The application is passively monitoring an NFC exchange for ...
0
votes
1answer
30 views
Using dvb-t device as rtl-sdr
I am wondering if I can use that dvb-t device to listen 48-836 mhz?
if it's no, why?
thanks..
4
votes
2answers
175 views
How is a crossed-ellipse display generated from FSK?
What is the algorithm or circuit needed to generate a (vintage?, retro?) crossed-ellipse display from RTTY and/or 2FSK signals?
(as per the (obsolete?) questions in some FCC exam pool)
(assume ...
0
votes
0answers
33 views
Gnuradio loopback flowgraph is not working
I found the below uhd_two_tone_loopback example (which is one of the gnuradio provided examples) and I am trying to run it, it runs but I can't receive signal.
EDIT:
I mean when I run the program I ...
1
vote
1answer
55 views
Controlling the number of samples
In the below simple qpsk_tx_uhd flowgraph I am trying to create a slider to control the number of samples but got a bit confused with which parameter I should be ...
2
votes
3answers
114 views
Under what circumstances does intermodulation become an issue in a filter after LNA setup?
I'm reading about using software-defined radio for picking up ADS-B signals at 1090MHz. There is this blog which considers (among others) a setup as follows:
...
1
vote
0answers
63 views
Capturing Bluetooth / WiFi on an SDR
I have a question, right before purchasing SDR for some tests:
Commercial hardware for bluetooth (even Ubertooth) allows you to receive packets on a 1MHz channel. Which practicaly means that if you, ...
0
votes
0answers
29 views
What the difference preamble and access code?
gnuradio packetize using access code for start sync packet, but another example attach the preamblee, so what the differences preamble and access code ?
0
votes
0answers
39 views
A gnuradio program that can output some arbitrary waveform read from a file containing I/Q values
I am trying to figure out how to create a gnuradio program that can output some arbitrary waveform read from a file containing I/Q values.
I would highly appreciate any guidance in this topic. Simple ...
0
votes
1answer
43 views
How to output a CW tone or a Broadband Noise in GnuRadio?
Kindly, can anyone show me how to output CW tone or a Broadband Noise in GnuRadio in a sort of simple flowgraph if possible?
Update:
So, what I did is I tried not to overthink the whole issue here ...
1
vote
0answers
36 views
How FEC works on GNU Radio
I am new to GNU Radio.
I need some reference to how to use FEC block in GNURadio.
When I try to make encoder and decoder without modulation, its work as well, but when I using modulation and add ...
1
vote
2answers
81 views
What to take in consideration when buying an RTL SDR dongle? (Amateur)
I want to buy an SDR RTL USB dongle and I'm looking for one on Amazon. I currently saw ones from 100 MHz to 1.7 GHz.
I can't decide and I know almost nothing about radio, but I want to experiment ...
1
vote
0answers
50 views
Trouble with osmocom source
I'm having trouble running a simple flowgraph with an osmocom source and a qt gui sink. If I run the file with a waveform generator instead of the osmocom source, all is well, the plots appear as they ...
0
votes
0answers
54 views
No module named 'analog_swig' [duplicate]
I know guys you gonna tell me tat there is something wrong about GnuRadio or Pybombs installation. Well, this is my third time during the past 48 hours I reformat the OS of my mini pc fitlet2 mint ...
2
votes
1answer
107 views
Can I capture stereo IQ signals from WebSDR?
When I set my sound device to record from the monitor/loopback source, I can capture the signal from WebSDR in my browser in an application like Audacity.
Looking at the captured signal more closely ...
2
votes
1answer
53 views
SDR as an oscilloscope
Can a SDR be used as a general purpose AC oscilloscope with appropriate attenuation at the front end.
Have in mind a capacitor to block DC voltages, large resistor say 10 Mohms to limit current and ...
0
votes
0answers
39 views
No module named _osmosdr_swig [duplicate]
I am trying to run GnuRadio python code in my python web server and got the "No module named _osmosdr_swig" error. Please, what is the cause for this error?
I know it sounds like so obvious that I ...
2
votes
2answers
172 views
No module named 'gnuradio'
I encountered with the "No module named 'gnuradio'" error while I was trying to run GnuRadio python code in my python web server.
And this is my gnuRadio generated code:
...
2
votes
1answer
113 views
Merging gnuradio generated python code into the Python web server
I am trying to figure out how I control a Software Defined Radio over a network, and stream the received baseband samples from my remote hardware back to the gnuradio.
What I'm trying to do here is, ...
2
votes
0answers
49 views
HackRF One and IoT overloaded?
I'm transmitting Z-Wave frames using HackRF One in loop, one frame every second. Has anyone clue why are some frames not transmitted? You can see several too long gaps between frames on Waterfall (...
2
votes
1answer
113 views
How does one know how a signal has been modulated
I am trying to intercept signals from a drone remote controller and decode them. Before I can do this I need to demodulate the signals. All I have is radio data from the transmitter's operating ...
3
votes
1answer
70 views
Why is GNU Radio “stuttering” with this flow graph?
I have a GNU Radio Companion flow graph, where I have the following connections:
440Hz cosine wave
throttle block
audio sink
All of the above blocks use the same sample rate (48KHz).
When I ...
2
votes
1answer
52 views
How narrow-band can a DVB-S2 signal be?
Using software defined radios I can generate and demodulate a DVB-S2 signal live. I'm wondering if I can use this to send single pictures over the air using as narrow BW as possible. Using QPSK and a ...
1
vote
1answer
65 views
Using Satnogs' *.ogg files in GnuRadio flowgraphs
I want to use the *.ogg files available in Satnogs' database to test demodulation software for several satellites (using gnuradio).
Can i use the ogg file source (available in gr-satnogs module) and ...
1
vote
1answer
106 views
Why does SDR# sound better than SDR console?
This is kind of odd. I just got my first SDR receiver and I noticed that one application (SDR#) sounds a lot better than another (SDR Console) when listening to stereo FM broadcasts through the same ...
2
votes
1answer
104 views
Where does this common spurious transmission come from? Is there a quality difference?
I decided to see what my ham transmissions look like on an SDR and was kind of shocked to see how much leaks out. The waterfall display is split between two handhelds during transmit. There are a ...
1
vote
0answers
49 views
How to limit frame transfer in Gnu Radio Companion?
I have as source a bit frame, then I modulate it, to finally transmit it with my HackRF. I can receive and decode it normally with another HackRF.
However I would like to limit to a number of frame ...
1
vote
1answer
72 views
Problem recording morse with sdr#
I have a problem with recording SWS-morse using SDRSharp and RTL-SDR.
I want fixed gain, not audio automatic gain control.
The problem is that all signal but the weakest will cause the recorded audio ...
5
votes
2answers
76 views
Digital transmission sounds
I'm playing with an RTL-SDR dongle and an LNA, on Linux Mint with GQRX and DSD
A lot of frequencies show digital transmissions, which the DSD is not converting. I don't whether it is a format DSD ...
0
votes
2answers
108 views
RTL-SDR: command or script to obtain power and deviation of an FM radio station
My project is to monitor the power and the deviation of 3 radio FM stations, sending this values into a MySQL database.
I can't stream directly the audio of the station, due to limited bandwidth.
So ...
1
vote
1answer
167 views
How I can build dvb-t/dvb-t 2 transceiver?
I need dvbt2 transreceiver.
I tried gnuradio with https://github.com/BogdanDIA/gr-dvbt.
The "apps/dvbt_tx.grc" is working.
But, video cannot transfer flexibly.
On gnuradio flow, I adjust multiple ...
6
votes
3answers
192 views
Long range communication with just 1W of power?
Is it possible, and how can I setup communication between stations 1000km apart from each other by using just 1W of transmission power?
By communication, I mean:
It can be text based
It can be very ...
2
votes
0answers
189 views
How to decode 2FSK signal with SDR?
I'm new to radio and SDR but, as a hobby project, I'm trying to decode a 2FSK radio signal received by an RTL-SDR that I sent using an SI4463 transmitter.
The record file contains 3 packets, but I'm ...
3
votes
1answer
130 views
RTL SDR “dark region”
I'm new to RTL SDR, and I noticed there's a "dark region" (around 700-900MHz), and I haven't figured out why this is.
My device's tuner is a Fitipower FC0012, where could I find the pinout and ...
3
votes
3answers
134 views
What equipment do I need to receive radio and connect to PC for listening
A great many moons ago, I spent a 24 hour period with a HAM radio connected to a PC, and listening to transmissions from a massive number of sources.
Some of the transmissions included Morse, RTTY, ...
5
votes
1answer
148 views
FM spectral amplitudes during silence
General setting
I'm playing around with an RTL-SDR and recently captured some FM spectrum in Hannover, Germany. I want to undersand what's going on, so I've read a lot about FM and its spectra, but I ...
2
votes
0answers
407 views
LimeSDR Mini + Raspberry Pi 3 B+ Transmission problem
I am new at this. I would like to transmit an audio signal cleanly using WBFM but I see two signal peaks occur around my fundamental frequency when I start transmitting.
In this case I am using a ...
6
votes
1answer
136 views
SNR measurement for a BPSK/QPSK signal
I have created a software (gnuradio) that performs modulation/demodulation and supports a number of modulation schemes and error correcting codes. I'm in the process of evaluating the BER vs SNR for ...
-4
votes
1answer
86 views
where to look for (live or recorded) air traffic conversations for a specific area? [closed]
I am wondering if there's any chance to get a short fragment of ATC/pilot radio exchange of any flight to/from small airport of Talkeetna (Alaska). This airport seems to be not present on liveatc.net, ...
0
votes
2answers
2k views
HackRF + Amplifier = HF/VHF QRP Radio?
Do you think it would work to combine a HackRF One and an amp like the following to create a QRP SDR?
Link to eBay
Output of HackRF is approximately 10dBm, which fit's this amp nicely...
What is ...
6
votes
2answers
226 views
Advantages of IQ generation at Mixer Stage or within FPGA for SDRs
I draw two possible architectures for Software Defined Radios below.
In the first architecture, I,Q signals are generated at the mixer stage and two ADCs are required. The FPGA down-samples the ...
5
votes
1answer
418 views
GNU Radio sinusoid multiplication does not produce perfect results
I created a simple sketch in GNU Radio that multiples two signals. One is a sine and the other is cosine. I paste a screenshot of it and its results below.
I have heard that in DSP, we can do almost ...
2
votes
2answers
494 views
Fast TCP/IP radio modem on UHF band
I'm interested if it is possible to have a data radio modem that works on the UHF band 400MHz for TCP/IP communication.
What I have in mind is something similar to a router, but using UHF band for ...
3
votes
1answer
139 views
How high an SWR can the USRP 2901 (B210) handle?
I connected a USRP 2901 (B210) to an amplifier I designed. The USRP seems to shutdown every time I try to transmit. I guess I messed up with the input impedance matching on the amplifier. Is it the ...
5
votes
2answers
63 views
Weak signal digital modes and clock synchronization
Why to some weak signal digital modes (jt9, jt65, etc.) require knowing a clock time? Does knowing this clock time provide any gain in signal detection ability? (lower required S/N?)
What clock ...
4
votes
2answers
96 views
Can a Digital Down Converter, at the same time, generate I,Q streams & Downconvert?
A Digital Down Converter (DDC) is usually used to convert Real Digital Signals at a high frequency to baseband (centered around 0Hz). DDC does this so by producing negative and positive frequencies.
...
4
votes
2answers
275 views
Sampling a 50 MHz Max Frequency 50 MHz BW Signal with a 50 MSps ADC
I paste below a superhetorodyne based Software Defined Radio Architecture for an Rx channel below.
Suppose the IF signal has a max frequency of 50 MHz and 50 MHz IF BW. In that case, is it possible ...
8
votes
2answers
696 views
IQ imbalance after quadrature mixing
What is IQ imbalance in the output of complex or quadrature downconverter/demodulator/mixer? What are the causes and effects of IQ imbalance? (A spike in the spectrum display of RF noise?) Are there ...
4
votes
2answers
173 views
SSB filtering in the frequency domain?
I'm not sure whether it's more appropriate to ask this question here, or in the dsp.stackexchange. But I'll try here first.
There seems to be a lot of information available on the filtering and ...
