Questions tagged [rtl-sdr]

Discussion related to the rtl-sdr project, which enables certain television dongles and other hardware to be used as a cheap SDR receiver

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3answers
266 views

How to increase the range of the spectrum analyzer in SDRSharp?

I'm trying to visualize the frequency band utilization during a GSM phone call using SDR. Ideally, I would like to plot the whole 900 MHz range, i.e. 876-959 MHz. However, even setting the zoom to the ...
6
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3answers
2k views

Noise & shielding, SDR Dongle

First, I'm very new to SDR. This may turn out to be really obvious. I just want to verify my thoughts before I spend more dollars. I have a USB dongle with the RT28xx in it. Works great. Side by ...
0
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1answer
29 views

How to analyse the distribution of the noise being received by my RTL-SDR device?

I'm very new to RTL-SDR and signal processing in general, but have managed to get my device (NOOELEC NESDR Mini) working and data into Python (via the pyRTLSDR library). I am able to output a complex-...
6
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1answer
992 views

Cell Tower distance measurement

I am developing a hobby project to detect/measure the distance between my cell phone and a cell tower (GSM tower). I am newbie. I don't even know whether this is possible or not. I have following ...
2
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2answers
209 views

rtlsdr - hearing an FM broadcast on different frequencies

There is an FM station in my city which transmits at 105 MHz. Today I discovered that I can also hear it quite well if I set the LO to 32.6 MHz and then shift the signal a bit. I'm using an rtlsdr ...
0
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1answer
49 views

How to get the "real" number of samples coming in an sdr

so I am fairly new to this SDR and dsp thing, I am working on a project that calculates the ppm and adjusts the offset, now I kinda got the idea of how to calculate the ppm after going through the ...
5
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1answer
230 views

Failing to detect Hydrogen line with 105cm dish

I've seen many examples of roughly 1 metre sized dishes being used w H+ sawbird and an SDR to detect and analyze Hydrogen line signal, and have been trying myself but can't seem to get anything beyond ...
4
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2answers
330 views

Problem with sample rate

So I am working on a project that involves me to check real time difference between samples.I am fairly new to this so after a bit of researching I wrote a simple python script for it, here is the ...
0
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2answers
51 views

Not able to understand some operations in rtlsdr library in python

Here is the part of the program I am having problems with: samples = sdr.read_samples(16*1024) power, _ = mlab.psd(samples, NFFT=1024, Fs=sdr.sample_rate /1e6) ...
0
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2answers
88 views

How do I set the RX frequency on a R820T/ R820T2 based SDR

My question relates to the specific programming of an R820T/ R820T2 based SDR for a specific frequency. I'm trying to build a self contained and auto initializing Raspberry Pi 4-based (ignore that ...
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2answers
3k views

GNU Radio does not run flow graph

I am sorry but yet again a question about GNU Radio. (I just started following some tutorials a couple of months ago and am learning about it. I am unfortunately not that proficient in it yet, but I ...
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0answers
196 views

GNU Radio FM Receiver does not work on Ubuntu 20.04 nor on Windows 10

GNU Radio v3.8 with Qt-GUI on Ubuntu 20.04 Before starting on something new I always test my setup with this GNURadio hello world flow graph which I know for sure, that it used to work. The other day, ...
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0answers
144 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
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1answer
237 views

Heterodyning complex values in gnuradio

I have been working at educating myself on how SDR and GNU Radio works. In order to demonstrate heterodyning, I set up a flow-graph consisting of 2 signal generators, a Multiply block, and QT GUI ...
1
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1answer
96 views

Adapt old AvermediaTV DVB-T tuner as SDR

I want to adapt the DVB-T AverMedia TV Pilot" tuner as a software defined radio, but it is not built on a RTL chip, so the question arises, is there some kind of driver to use my tuner as a radio?...
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0answers
94 views

Capture Uplink GSM packets using 820T2 and SDR

I am an extreme beginner with SDR. I am trying to use the 820T2 & SDR device to capture uplink gsm packets sent by my phone to the nearest Base Station. I have an Rx Monitor App installed on my ...
2
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2answers
358 views

Broadcast signal deviating with time

I've been just scanning through the HF band at night seeing what all I can pick up, and I'm trying to figure out a particular signal. I'm using a VHF discone, which isn't ideal, but it works well ...
4
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1answer
85 views

How to track down and neutralize this apparent mixer creating noisy emissions around my signal?

When I transmit, it there seems to be something mixing and reflecting my signal. For example, when I transmit on 14.300 MHz, I see signals above my transmitted signal at at 14.500, 14.700, 14.900, etc....
0
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1answer
360 views

Implementing FM receiver using GNU Radio C++ API

This is my first ever experience with GNU Radio. I am trying to implement a simple FM receiver shown below with its C++ API. I seem to have pedantically deconstructed this receiver into its smallest ...
2
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3answers
377 views

Problem with RTL-SDR v3 dongle - unusable PLL

I own an RTL-SDR v3 USB dongle (official version from rtl-sdr.com). I've successfully used it for decoding weather satellites past year. I use (GQRX + Audacity)/(Arch Linux 64bit) + (WXtoIMG)/(Windows ...
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1answer
1k views

Transposing gqrx setup to rtl_fm?

Need to duplicate gqrx settings in rtl_fm command line switches. Review of rtl_fm docs has yielded no joy. gqrx configuration: Freq 156.425 Mhz Filter: Wide Mode: Narrow FM AGC: Fast Squelch: -58.5 ...
9
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3answers
1k views

AIS and RTL-SDR Dongles

I am looking for an Windows-based AIS Decoder for RTL Dongles. Currently, there is a solution available using GNU Radio and SDR# but it is complicated to set up and keep running. ADSB has a dedicated ...
4
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1answer
3k views

Why doesn't GNU Radio Companion's wx Constellation Plot doesn't give me the clean QAM constellation I get from its Qt sibling?

Using a RTL2832U USB dongle, I set up GNU Radio to produce a constellation plot of APRS traffic on 144.8 MHz. The result is what I expected: So far, so good. Why not try the same thing using the wx ...
0
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1answer
260 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 ...
3
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2answers
272 views

HDMI to VGA adapter interference with 138.5 MHz carrier

(sorry for my English) I'm using the HDMI to VGA adapter on my pc, and receiving weather satellites on ~137 MHz with RTL-SDR V3. There was a problem: my VGA adapter creates a powerful signal, who ...
4
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1answer
1k views

FM Receiver on GNU Radio with RTL-SDR fails to produce any output sound

Here is how the FM Receiver I made using the GNU Radio Companion. (Basically, I was following this tutorial by VYE6Y on youtube.) FM Receiver Problem: Unfortunately for me, the GNU Radio gives no ...
7
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3answers
3k views

Using an RTL-SDR as a spectrum analyzer

I've been trying to get into RF electronics, but one thing that is holding me back is lack of test equipment. I have an old analog oscilloscope, but that doesn't help much for things like verifying ...
1
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1answer
182 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?
7
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4answers
783 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 ...
1
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1answer
107 views

Ham radio listener is split up on old hardware

I'm trying to get a ham radio listener working with RTLSDR on an old Pentium 4. Unfortunately it is playing for a few seconds, then not playing for a split second, very split up. Is there a way I can ...
2
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2answers
396 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 ...
1
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2answers
76 views

Batch sampling SDR

I am using RTLSDR on macOS with Cubic SDR, it works great and is very intuitive. Now I want to do a frequency envelope analysis where I need to basically 3-d plot intensity versus frequency and time. ...
1
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0answers
201 views

Compare signal strength with Software Defined Radio

I want to compare field strength with an RTL-SDR dongle or HackRF One. With comparing I mean being correct relative to one another, like if I know field strength of one in mW/m^2 then I know the other....
2
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0answers
90 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
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1answer
118 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..
2
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1answer
986 views

how to select an SDR stick remotely from gqrx via soapysdr

I have a raspberry pi 3b on my roof (in a plastic box) with two SDR sticks attached to it. On the raspberry pi the "soapysdr" program runs. ...
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0answers
420 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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2answers
441 views

How much power does an RTL-SDR draw?

Background: Last night (and the night before) I was playing with my RTL-SDR and GNU-Radio again. Working with my FM Receiver, (which was working previously by the way), I detected that last night I ...
1
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2answers
136 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 ...
19
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5answers
9k views

SDR: Quadrature demodulation vs direct RF sampling

I see that many SDRs use a quadrature demodulator and sample I and Q signals. But is it possible to downconvert the RF signal instead, sample it with only one ADC, and get the same capabilities of ...
0
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0answers
239 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 ...
0
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0answers
147 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
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3answers
895 views

VHF 50 Ω Antenna Over 75 Ω TV Coax

I have a 50 Ω VHF airband antenna which I’m planning to install in my loft, for use with a RaspberryPi-based RTLSDR scanner/receiver. I already have a UK-standard UHF/Freeview antenna using standard ...
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2answers
166 views

Reset the sps on symbol sync block GNU Radio

I'm using symbol sync block (symbol_sync_ff) on my project and i use many different sps values that i need reset on runtime. I'm trying to reset sending clock_est tag. Is this the right way to reset ...
1
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1answer
125 views

Unitrunker Receivers Not Displaying Fields

I've been playing around with RTL-SDR and Unitrunker attempting to get a police scanner working. I followed the tutorial here: https://sites.google.com/site/policescannerhowto/ Everything works as ...
1
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1answer
124 views

How can I improve my Es'Hail 2 reception?

I'm using an RTL-SDR to receive Es'Hail 2. My chain is as follows in order: 60 cm TV Satellite dish pointing 2 degrees off Es'Hail 2 Universal LNB (from TV company, not really a stable frequency). ...
3
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2answers
117 views

Tips for HF Antenna with house near AM transmitter

My back garden is very small - about 500sqft. I also live near an AM transmitter and requires an AM filter. I would appreciate some general tips on the best approach to receiving HF signals (Ham and ...
3
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2answers
659 views

RTL-SDR dongle - what antenna should I use for APRS receive only?

I was following this guide to setup an iGate using an RTL-SDR dongle and a Raspberry Pi. It worked, and I have been able to test it by seeing some APRS packets from a separate transmitter (Arduino+...
1
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1answer
2k views

RTL-SDR - rtl_fm: undefined symbol: rtlsdr_set_bias_tee

On a Raspberry Pi 3 B+ running Raspbian Stretch, when I run this command, timeout 115 rtl_fm -d 0 -g 49 -M usb -s 32000 -r 32000 -F 1 -f 50.293M outfile.raw I ...
5
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2answers
110 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 ...