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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

0
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1answer
22 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 ...
6
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1answer
80 views

How to make a ferrite bar antenna for RTL-SDR?

I bought a RTL-SDR (blue one with little MCX antenna). I modified its Q branch, and can receive short wave radio with Degen 31MS antenna now. For MW, Degen 31MS antenna has a ferrite bar antenna ...
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2answers
165 views

How to attach a magnetic loop antenna to the 50Ω coax of an RTL SDR?

I'm planning to make a magnetic loop antenna mainly for receiving LW, MW, and SW radio broadcasting bands, as well as perhaps the 2.2km band and 630m band. (Not all of them with the same antenna, I'mm ...
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2answers
331 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 ...
5
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2answers
113 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
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1answer
86 views

Cell Tower distance measurement

I am developing a hobby project to detect/measure distance between my cell phone and cell tower (GSM tower). I am newbie. I even dont know whether this is possible or not. I have following hardware: 1)...
4
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5answers
225 views

How important is the impedance and resonance of a receive antenna?

I'm very new to shortwave radio, as evidenced here: Can an antenna be too powerful for certain receivers? I want to build a longwire receive-only antenna for the HF frequencies. I've been using ...
3
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2answers
68 views

FFT showing evenly spaced signals when tuned to ~56 MHz down to 25.680

I'm running GQRX on Mac OS X 10.11.6 hooked up to an RTL-SDR dongle. I noticed when I'm tuned anywhere between ~56 MHz on down to 25.680 MHz I see evenly spaced signals on the FFT. But when I tune ...
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2answers
209 views

Apartment antenna and rtl-sdr with upconverter

I'm just starter. I bought MFJ-1622 40-2M APARTMENT ANTENNA (I don't have access to the roof) I only have RTL-SDR with Upconverter (I'm on budget). I living on 10th floor and I will use it from my ...
3
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1answer
130 views

How can I determine if out of band interference is affecting my AIS reception?

AIS I am receiving ship AIS messages. These are low power, digital messages periodically sent on two marine channels close to 162mhz. This frequency is surrounded by FM broadcast, weather radio, and ...
5
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1answer
534 views

RX antenna and RTL SDR with upconverter ..How to hear something?

I mounted a small RX antenna (mini whip, bought from eBay) (on 10-th floor) and I want to try to listen to something. I bought a RTL-SDR with Upconverter which supports HF. RX antenna's operating ...
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3answers
596 views

Linux RTL-SDR waterfall via the command line

Using Raspbian (Debian) Linux on a Raspberry Pi 2, how can I view data from my software-defined radio via the command line over SSH? Is there an RTL-SDR client with terminal emulation?
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1answer
118 views

Choose the right dongle for NOAA images visualization with GnuRadio [closed]

I'm a newbie in such domain and I was reading some articles around the internet and what attracted me most is using the GnuRadio to see NOAA images using some cheap hardware. I looked further it ...
2
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1answer
339 views

Serialising a data signal with a Raspberry Pi

I'm working on a project to transmit and receive data by radio. For the transmission, I'm using a Raspberry Pi 3 and the NTX2B transmitter for the transmission. For the receiving end, I am using ...
2
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1answer
242 views

What kind of antenna design is this?

I've found an old antenna that once came with an HP laptop with a TV (DVB-T?) card. I decided to see if I can use that antenna for something else, so I opened it up and found the following antenna ...
1
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2answers
291 views

How to distinguish SDR 820T and 820T2 dongles on Linux?

I have bought an 820T2 USB dongle, but $ rtl_test detects it as Raphael Micro 820T chip. Can rtl_test distinguish the two? If not, how can I see, if the chip is ...
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1answer
84 views

RF connector between mobile phone and transmitter = complete shielding?

When connecting mobile to transmitter with RF cable: Does RF connector provide complete shielding for the transmitter signal ? Does it prevent the mobile from receiving other signals from other ...
2
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1answer
274 views

What is this Morse code-like station?

I’m trying to identify this signal at 928.807 MHz. A sample of the raw I/Q from gqrx is here (9.2 MB, .wav, 48000 Hz) and this is the waterfall: I’ve tried decoding some common digital modes (...
2
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2answers
1k views

Where can I find a listening guide for different frequencies and their usages to listen to on SDR?

I just got an RTL-SDR dongle by Nooelec and am using CubicSDR on Mac (which supports AM, FM, and SSB), and I'm in Canada. I'm able to easily find FM radio stations, but outside of that I'm not sure ...
5
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2answers
1k views

How to determine the PPM value of a NESDR SMArt?

a) Given that I don't have a frequency standard or other known transmitter available, what is the easiest way to calibrate the NooElec NESDR SMArt which is using a TCXO rated at 0.5 PPM.? I.e. to ...
4
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2answers
1k views

Where can I download NESDR Smart (NooElec) drivers for Mac OS Sierra?

Just bought this NESDR Smart USB dongle from Amazon in Canada. Wrote the company asking for drivers, but they sent links which didn't help. Anybody have a better place to download drivers for Mac OS ...
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2answers
2k 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 ...
2
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2answers
146 views

RF scanner w/ graphic output

I debated putting this question on the electrical engineering forum vs. here. I settled on here since I figured many of you amateur radio experts have probably wondered about this too. I am ...
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1answer
100 views

Signal booster with transistor

How can I make a simple signal booster without introducing too much noise? My first thought was to just feed the signal into transistor base (capable of 4GHz) through a 1K resistor. I could get a 1.2W ...
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1answer
660 views

RTL-SDR with SpyVerter - setup

I need some assistance in setting up a RTL-SDR with a SpyVerter upconverter, using SDRSharp. I have been using the RTL-SDR on its own with success. However, when I connect the SpyVerter (the side ...
2
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0answers
52 views

Capturing the key fob signal with SDR [duplicate]

Is it correct to assume that not all the key fob signals have preamble section? I am playing around with bunch of key fobs and I am trying my best to capture their OOK transmitted signals with RTL-SDR ...
5
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1answer
1k views

SDR with the Raspberry Pi

I wanted to explore digital modes by connecting a Raspberry Pi via audio cables to a transceiver. However, I realized that thanks to the clock generator, the raspberry pi can produce RF signals ...
4
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1answer
3k views

How to choose the right sampling rate and bandwidth for RTL-SDR dongle?

Receiving the frequency of 97.9 MHz I have a Terratec SDR dongle and I am trying to capture a radio frequency. The FFT window shows the frequency range from -500 to 500 KHz. Is there a way to ...
4
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1answer
272 views

ADS-B for Trains?

Is there any kind of technology similar to ADS-B for trains? I'm aware of HOT/EOT/DPU messages, but as far as I can see these don't allow you to see its location. I'm specifically wondering about the ...
1
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1answer
572 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 ...
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3answers
858 views

Improving VHF airband reception

I'm trying to receive VHF airband transmitted from a nearby airport via RTLSDR and having a hard time doing so. Obviously the stock antenna is useless in this situation. I tried building a quarter-...
7
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1answer
287 views

Confusion about SDR

I've just written code for the RTL2832 to receive and decode ADS-B packets (very cool!). I had some confusion about what is actually happening: Is the raw data coming from the USB dongle literally ...
2
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3answers
185 views

SDR for Spectroscope

I'm looking into getting a cheap SDR (perhaps the RTL-SDR RTL2832U) to use as a spectroscope, especially to test the frequency output of Baofeng radios. I currently have reason to believe that one of ...
2
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1answer
428 views

Adding a panadapter via SDR

I've become very accustomed to the waterfall display on my SDR, especially for digital modes over HF. I'm thinking about tying into the IF on my IC-718 and connecting to an SDR to add a waterfall to ...
2
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1answer
95 views

quadrature demodulator on a chip

I am searching for a single chip/small board solution for quadrature demodulation to sample IQ signals with an integrated ADC for DC-50Mhz frequencies. The reason for that is that I found this sdr ...
2
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1answer
492 views

QSSTV/Hamlib and RTL-SDR/HackRF One

I came across QSSTV today. It's a relatively new Linux program for SSTV and DRM. The config suggests that it can use a number of different external radios as transmitters. What I'd really like to try ...
5
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3answers
771 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 ...
6
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1answer
565 views

Video transmission between ATV and SSTV

I'd like to experiment with amateur video transmission in a setup halfway between ATV and SSTV. 480 lines of B&W image would be sufficient with 10 FPS, and I'm interested in both digital and ...
6
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1answer
870 views

How to detect a tone on an FM Frequency using an RTL SDR receiver?

I'm transmitting a simple tone which lasts 50 ms using an FM transmitter. I can see clearly this tone being received on my RTL-SDR device when I look at a spectrum graph (using GQRX). I need to call ...
3
votes
1answer
423 views

Receive antenna design for a small apartment

I am looking to make a simple receive antenna from some wire, and I have some questions about resonance. Being that this wire can only be so long (about 3 meters maximum, as it must fit inside my ...
2
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1answer
113 views

Power surge on hub when using NooElec nesdr mini

I'm trying to set up sdrSharp on my PC using a NooElec nesdr mini for the receiver. I've read a bunch of setup instructions which all suggest using Zadig to install the usb drivers for the receiver. ...
5
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1answer
155 views

Images up and down the spectrum

I brought an rtl-sdr USB stick to a foreign country. I am listening with gqrx, and I am surprised to find audio (e.g. television or radio) up and down the spectrum, up to 600, 700 and 800 MHz ranges....
3
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2answers
7k views

How to play spectrum recordings made with rtl_sdr in gqrx?

I have an R820T DVB dongle and the rtl_sdr software on a linux computer. I can listen to various frequencies using the gqrx software which uses the rtl_sdr library as a device driver for the USB-...
6
votes
1answer
424 views

SDR - FM Radio station interference

I want to learn about software defined radio and how wireless transmission work in general. So I started messing around with SDRSharp and a little antenna I bought. I figured I would start looking ...
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 ...
3
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1answer
534 views

How to connect this Active Antenna Loop and 100MHz Upconverter?

I have bought the two devices in the image. The 100MHz Upconverter with a SMA connector is used to upconvert HF/MF signal for RTL-SDR to demodulate. I found that there is signal from the antenna (...
8
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1answer
309 views

Why do SDR control apps have two frequency settings?

Why do many SDR control apps have two frequency settings, even when the app is designed or set up only for listening to or decoding one signal? Should the two SDR frequency controls be set ...
5
votes
1answer
636 views

What should I look for in an antenna for a DVBT Dongle used for SDR?

I use a cheap DVBT dongle that I control via RTL-SDR. Right now a very basic setup. The general consensus seems to be that a long usb cable should be used (to keep noise from the computer away from ...
17
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5answers
6k 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 ...
7
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3answers
8k views

How can I reduce the noise coming in from an RTL-SDR dongle?

I've recently received an RTL-SDR dongle, and I'm picking up a lot of noise that is probably coming from my PC, especially a lot of "spikes" on the 2M band. I've already started using a USB extension ...