Questions tagged [software-defined-radio]
Radio devices that use digital signal processing in place of analog electronic components to manipulate RF signals.
219
questions
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0answers
21 views
2GFSK digital filter bandwidth calculation
I'm working on a S2LP from ST and I am configuring the RX digital filter.
I need to calculate the bandwidth of the signal which has 2GFSK modulation.
Do you think the code below is correct for ...
1
vote
1answer
78 views
How does an Airspy HF+ Discovery compare to a “real” radio?
I was looking for a secondary radio for RX only and I thought a SDR may be a better option. I read about upconverters but then I saw Airspy has a SDR with the upconverter onboard, and claims to have &...
1
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3answers
79 views
Practicality of SDR-based TX/RX
When it's not possible to be at the same location as a TX/RX appliance, some form of remote control is needed.
There's basically two ways to TX/RX:
classical radio appliance, with or without digital ...
2
votes
2answers
183 views
What is the current state of the art in CW filters?
In the 1970s I made a CW “filter” based on a phase locked loop that detected a specific audio frequency, and this drove an NE555 oscillator: the result seemed at first like a “zero bandwidth” CW ...
2
votes
1answer
66 views
Can these in-band spurs from rpitx be eliminated somehow?
I'm putting together a 2m NBFM transmitter/receiver combo using rpitx and rtl-sdr. During testing my low-pass filter I discovered that rpitx is generating spurious signals within and around the band (...
6
votes
4answers
374 views
How can quadrature mixing adjust the phase of all frequencies by the same amount? Can it be done in the digital domain?
This came up in some feedback I got when I tried to answer What is IQ in the context of SDRs? and revealed some of my own misunderstanding.
Initially, I gave an answer something like (paraphrasing):
...
2
votes
0answers
42 views
Receiving and decoding RDS in GnuRadio
I'm new in radio, so I started with seemingly easy task - receive and decode RDS data. I use GnuRadio to understand the concept of working with RF signals. So according to standard RDS receiver looks ...
0
votes
1answer
33 views
Does DCS intefere with SDR reception?
Does digital coded squelch (DCS) interfere with the analog-to-digital conversion in software-defined radios (SDRs)?
I noticed that I can receive normal transmissions with my SDR just fine, but I have ...
4
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5answers
156 views
0
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1answer
78 views
GNURADIO: What does the complex output of an osmosdr source translate to?
Warning: Noob question.
I'm new to Software Defined Radio.
My aim is to write a program that tells me the signal strength of a radio emitting source (I'll use three such sources and then try to ...
2
votes
2answers
108 views
Whats wrong with this radio signal?
I have a code that sends a beacon every 1 minute with a data-rate of 1200bps (BPSK-G3RUH). I do receive the signal using a custom software defined ground station that also decodes the beacon. After a ...
0
votes
2answers
100 views
Imaging with radio Frequency
Is it possible to image bones and tissues with radio waves (2.7GHz-5GHz) with a tiny radio frequency source and on one side and a receiver on other side which can image the data through a PC mediated ...
-3
votes
1answer
48 views
Can the power output of a software defined radio be adjusted? [closed]
Some SDR transmitters have a very low power output.
Can their output be adjusted?
1
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3answers
125 views
SDR transmit on more than one frequency
I'm new to SDR. Is it possible to transmit on more than one frequency, and if so what do I need?
more on computer type network
side one for each 800, 2.4, 5, 60
How can I get more than one SDR to ...
1
vote
1answer
80 views
Receiving different gain values on two RX channels on Ettus USRP B210
I am transmitting a continuous wave and using one USRP B210 with the kitchen_sink tool in order to save the received samples from two RX channels (v.3.15.0)
When I look into the received signal on ...
1
vote
1answer
71 views
Can I get non demodulate IQ signals from WebSDR
I want to take a non demodulate audio signal from webSDR portals (http://www.websdr.org/). In order to try to feed these in DREAM DRM Radio software or GNURADIO.
Could be cool almost try it for ...
1
vote
2answers
90 views
Advantages of IQ mixer versus baseband sampling SDR architectures?
What might be the advantages, if any, of HF SDR architectures that use a mixer between the ADC/DAC and RF, versus those that sample or generate RF directly at baseband with a fast ADC or DAC?
Are the ...
1
vote
1answer
90 views
How is gqrx producing audio?
How exactly is GQRX converting signal in any frequency to produce audio output?
Is it actually done by gqrx or some other element of the stack?
1
vote
1answer
254 views
How to send DMR SMS using MMDVM modem or hackrf?
I have a baofeng DMR radio with SMS feature, and since there is not much DMR radio owners in my area I want to do something myself.
The easiest thing I can do I thought is to send myself some SMS as ...
0
votes
1answer
87 views
Most accurate way to measure signal power with (cheap) Spectrum Analyzer
I am using an USRP X310 which is unfortunately not calibrated and the specs given are only very vague.
Hence I would want characterize the device with first-order measurements. Unfortunately I only ...
1
vote
2answers
175 views
Can I use a “bunny ears” TV antenna for RTL-SDR?
I'm trying to get into SDR and was planning on buying an RTL-SDR. For an antenna, I was thinking of using an old set of bunny ears I have lying around. However, I first want to make sure that they'll ...
7
votes
4answers
323 views
DIY SA612 + RTL-SDR HF receiver: good on laptop, but huge wideband noise on Raspberry Pi
I recently built a SA612 mixer for HF reception. I used an USB-frequency oscilator to shift the incoming frequency up by 28.8 MHz.
I used a random wire antenna outside my balcony and connected it to ...
0
votes
1answer
49 views
Shifting frequency outside of the band
In theory when i need to shift some frequency i just multiply that signal by some sin or cos wave with the right frequency and than apply LPF or HPF.
But when there is a wideband complex signal with ...
0
votes
0answers
62 views
Is there any 2.4 GHz tuner ICs for SDR receivers?
I have a hackrf one sdr, which i use to transmit test signals.
I am using ISM bands, so I can omit transmitting my callsign, checking correct sub band (FM, digital) etc.
And one of most interesting ...
0
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1answer
75 views
3
votes
1answer
84 views
Turning raw APT data into an image
I apologize if this question is a little out of scope for the amateur radio stack exchange but I feel like it fit better here than over in any other forum.
I have successfully parsed raw PCM data out ...
1
vote
1answer
76 views
Gnuradio AM broadcast receiver distorted audio
I have been trying to build a gnuradio AM broadcast receiver, but without success. I have tried a lot of combinations, but all of them produce a very distorted audio. I have an NBFM receiver using the ...
1
vote
1answer
88 views
audio problem with SDR on MacOS
I'm experimenting with SDR on MacOS High Sierra. Trying both CubeSDR and GQRX and experiencing similar issues with both. The applications seem to work, but the audio is choppy and chipmunk-like. ...
3
votes
3answers
196 views
What is the typical latency of a SDR setup running on a desktop computer?
It's well-known that the signal processing of an SDR adds a significantly amount of latency, the SDR software on the computer adds more latency due to data buffering, FFT, decoding, demolutaion, audio ...
5
votes
3answers
217 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
51 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
69 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..
5
votes
2answers
261 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
41 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
60 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
192 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
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0answers
197 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
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0answers
43 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
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0answers
45 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
2answers
149 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 ...
2
votes
0answers
102 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
100 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
79 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
156 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
174 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
343 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
113 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
2k 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
170 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
82 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 (...
