Questions tagged [software-defined-radio]

Radio devices that use digital signal processing in place of analog electronic components to manipulate RF signals.

Filter by
Sorted by
Tagged with
3
votes
4answers
434 views

Is there an FT8 or other weak-signal digital mode specification available?

Is there a complete and programming language independent specification available for the FT8 digital mode? Detailed enough to implement both transmit and receive SDR software from scratch in two ...
1
vote
1answer
68 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
vote
3answers
74 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
181 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 (...
5
votes
2answers
260 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 ...
1
vote
2answers
432 views

How to make a software defined radio using USRP and GRC

I want to make a software defined radio, based on the hardware device shown in the schematic diagram below. I don't have a strong background in telecommunication engineering (I'm an electrical ...
6
votes
1answer
187 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 ...
9
votes
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
votes
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 ...
4
votes
1answer
663 views

Can a WLAN device be used with GNU Radio?

Can I use my wireless ethernet card with GNU Radio? I have a Broadcom BCM4311 mini PCIe, and Debian / Kali 2.0 Linux.
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): ...
1
vote
2answers
161 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 ...
4
votes
5answers
156 views

What is IQ in the context of SDRs?

What is IQ, in the context of software-defined radios (SDRs)?
2
votes
0answers
41 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 ...
1
vote
1answer
244 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
75 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
votes
3answers
2k views

How to receive a signal from multiple sources simultaneously (helical antenna)

I'm working on a system (theoretical at the moment) whereby I wish to receive data from multiple sources all transmitting at the same time. I've read that a helical antenna is capable of this. I'm ...
0
votes
2answers
99 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 ...
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
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
1answer
79 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 ...
4
votes
2answers
2k views

What is a panadapter?

To what does the term "panadapter" refer? (Physical hardware or software?) How did the term "panadapter" originate as related to radios or electronics? How is the term "panadapter" different from ...
5
votes
1answer
183 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 ...
-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
vote
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
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
86 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
83 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
votes
4answers
322 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
vote
2answers
169 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 ...
0
votes
1answer
48 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
votes
1answer
75 views

what is the center frequency

in GRC for this source block ?
3
votes
1answer
83 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 ...
2
votes
2answers
348 views

How link between gnuradio and baudline?

I want to create a sink block in GNU Radio which transfers the signal to baudline. My purpose is viewing SDR's received signal online. How should I program this block?
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. ...
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 ...
0
votes
2answers
148 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 ...
3
votes
3answers
194 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 ...
2
votes
0answers
400 views

Does anyone repair Flex radios other than Flex Radio?

A local ham that I have an evening sked with on 75m (Paul, W0EBV) sent his Flex 5000 SDR transceiver to Flex Radio Systems to get it repaired a few months ago. However, it seems that Flex is either ...
5
votes
3answers
216 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
67 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..
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
191 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
189 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, ...
2
votes
3answers
1k views

SDR CB Transmission

I have a CB radio and I occasionally mess with a cheap SDR Dongle I have. I can pick up CB transmissions no problem but would like to be able to broadcast from my SDR. Is there any way to do this? I ...

1
2 3 4 5