Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

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

112 questions
19
votes
5 answers

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 digital postprocessing? So if we want to observe…
BarsMonster - R2AYN
  • 376
  • 3
  • 14
11
votes
2 answers

Can an amateur use cellular technologies with SDR?

Software Defined Radio is opening up many new possibilities for amateur digital modes. One family of technologies that interests me is cellular. 2G GSM voice/sms and 2.5G GPRS data has been proven to work with OpenBTS on a USRP SDR using licensed…
JC Hulce
  • 901
  • 5
  • 16
10
votes
1 answer

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 samples of the ~1090 MHz wave? Or is the carrier…
Nathan Wong
  • 203
  • 1
  • 4
10
votes
3 answers

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 solution called RTL1090 that connects directly to…
Mark Cupitt
  • 201
  • 2
  • 7
9
votes
1 answer

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 differently or the same? If different, how much for which…
hotpaw2
  • 13,116
  • 6
  • 40
  • 72
9
votes
3 answers

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 cable instead of plugging the dongle into the PC.…
krzysz00 KF5SOQ
  • 541
  • 1
  • 3
  • 10
8
votes
1 answer

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 increase this or it depends on the dongle and is fixed?…
Jack
  • 389
  • 1
  • 3
  • 13
7
votes
3 answers

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 filter frequency or looking at harmonics. So far I…
user9103
  • 93
  • 1
  • 5
7
votes
7 answers

Why is 20m band waterfall showing signals every 50 kHz?

I'm very new to shortwave listening and just got to grips with my RTL SDR HF dongle. Last night while on the 20m band, there were signals exactly every 50kHz, starting exactly at 14.000MHz, then at 14.050 MHz, 14.100 Mhz and so on. Google said they…
rcx935
  • 401
  • 2
  • 9
7
votes
4 answers

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 the center-pin of a car antenna mount, and used a…
比尔盖子
  • 569
  • 2
  • 16
7
votes
1 answer

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 coupler to work with the internal antenna of the…
jac123
  • 73
  • 4
6
votes
1 answer

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 range is 100kHz - 30Mhz. If I want to listen…
kesrut
  • 185
  • 3
6
votes
2 answers

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 where to look for interesting frequencies to listen…
user9315
6
votes
3 answers

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 side I have a 35 year old Azden 2 meter receiver. …
David Hoelzer
  • 1,025
  • 1
  • 9
  • 30
6
votes
1 answer

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 analog methods. I'd prefer if I wouldn't have to buy new…
dnet
  • 165
  • 6
1
2 3 4 5 6 7 8