8
votes
Accepted
Is it legal to transmit with HackRF one?
You'll need an experimental radio license (Versuchsfunk) from Bundesnetzagentur link for research operation.
For demonstration/teaching purposes, a demonstration radio license (Demonstrationsfunk für ...
- 16k
7
votes
Fast TCP/IP radio modem on UHF band
As you might suspect, the data rate impacts the required RF bandwidth. Besides the data rate, the modulation method, encoding, packet overhead, duplexing, and other factors ultimately determine the ...
- 18.6k
7
votes
Is it legal to transmit with HackRF one?
As for other legal alternatives, one might be transmitting inside a suitably shielded Faraday cage. I’ve seen such facilities at labs where various prototype and pre-production (and competitors?) ...
- 13.3k
7
votes
How is the Hackrf able to achieve 20MHz of bandwidth with an ADC that only allows 22Msps?
The Nyquist limit is half the sampling rate because otherwise you can't distinguish a signal at a frequency $x$ from a signal at $f_s - x$ which starts 180° out of phase from the first one — they give ...
- 12.4k
6
votes
Accepted
Signal in the center frequency of my SDR spectrum always
That is DC offset, either in the analog to digital converters, or their driving circuitry.
The average voltage at the ADC's input is ideally exactly in the middle of the ADC's range, since this ...
- 51.7k
5
votes
Accepted
HackRF + Amplifier = HF/VHF QRP Radio?
Just to answer the second part of the question, you do not want an amplifier that has too wide a bandwidth, mainly to lower the complexity (and hence also the cost) of the amplifier.
All users of ...
- 4,599
5
votes
Accepted
HackRF Hardware
The RF architecture of the HackRF One is diagrammed here:
This is a bit elliptical so I'll explain what I read from it (describing the receive-mode operation; transmit is just the reverse). There ...
- 24.5k
5
votes
Accepted
How is the Hackrf able to achieve 20MHz of bandwidth with an ADC that only allows 22Msps?
Another way to look at it is that an IQ ADC is really taking 2 independent (not added together) samples per IQ sample. Thus the rate of information gathered is double from a just scalar sampling at ...
- 13.3k
4
votes
The amplifier does not work for hack rf one
HackRF has three amplifiers in the receive section. The first is a low noise amplifier (LNA) with fixed gain of 14 dB. The second is an Intermediate Frequency (IF) LNA with gain that varies from 0 to ...
- 51
4
votes
Loss of information and aliasing in superheterodyne receivers
Given a band limited signal, where there's no energy outside the frequency rate FL to FH, the Nyquist-Shannon sampling theorem tells us that there are two conditions you have to meet in order for your ...
- 357
3
votes
Loss of information and aliasing in superheterodyne receivers
For a radio / SDR that downshifts a signal to an IF / intermediate frequency band, wouldn't information be lost in the case that the original signal is above the IF sampling rate?
There's two ...
- 7,411
3
votes
using 3.10 gnuradio and hackrf to make a signal generator
As I explained multiple times before, pick a suitable sampling rate, connect your signal source to your Soapy HackRF Sink. Done.
(I enabled the display of what I entered in the fields for you. Your ...
- 16k
3
votes
Accepted
The amplifier does not work for hack rf one
There are three receive gain stages in the HackRF one. Two of them are on the MAX2837 chip (the ones controlled by "LNA gain" and "VGA gain"), and the third is the MGA81563 preamp, ...
- 12.4k
3
votes
Legal aspects of the HackRF one / SDR in Switzerland?
The device usually doesn't have anything to do with legality, it's what you do. So, rule of thumb: Without a license, you can't transmit – full stop.
I'm not quite sure about federal Swiss law, but ...
- 16k
3
votes
Synchronizing HackRF Ones at a distance
If you're using four independent GPS receivers as your time synchronisation source, you may be able to feed some version of the GPS 1PPS signal into the receiver, and recover it later in the data.
It'...
- 11.2k
2
votes
Accepted
Choose the right dongle for NOAA images visualization with GnuRadio
Picking up NOAA imagery is mostly a feat of constructing a good antenna than having a high bandwidth, or great clock. Thus, for reception only, build a nice helical antenna, and any cheap RTL Dongle, ...
- 16k
2
votes
Accepted
RF connector between mobile phone and transmitter = complete shielding?
Do you mean removing the antennas from each device, and connecting them directly with a piece of coax? Yes, that does provide complete shielding. Though you'd want an attenuator to avoid overloading ...
- 51.7k
2
votes
HackRF Hardware
As this is SDR, the HackRF hardware presents the received signal as I/Q to the computer. The actual demodulation is done in software.
- 2,157
2
votes
Synchronizing HackRF Ones at a distance
First synchronize all 4 clock generators in frequency using an external source (say, GPS or atomic clock derived into the 10MHz ref input). Start receiving continuously on all 4, and use the received ...
- 13.3k
2
votes
How is the Hackrf able to achieve 20MHz of bandwidth with an ADC that only allows 22Msps?
Are the two channels added together? Yes and no.
The whole point of collecting I and Q is so they can be treated as real and imaginary parts of a single complex sample.
This is one of the key methods ...
- 6,230
2
votes
How can I jam cell phone communications with gnu radio and hackrf?
Do you mean you want to put your phone and a small SDR in a faraday cage together such that the SDR only receives the phone’s emissions? If so, a metal lunch box should work for everything except the ...
2
votes
How is the Hackrf able to achieve 20MHz of bandwidth with an ADC that only allows 22Msps?
This is old I know and this may have been stated already, but when we normally think of Nyquist, we think of taking real samples of real signals. When you do that the signal had twice the bandwidth ...
- 21
1
vote
Unstable frequency generator using gnuradio 3.10
The videos and photos provided are of substantially different configurations so this isn't just one puzzle, it is many. In the last video, it appears the HackRF is being instructed to tune to 120 MHz ...
- 11
1
vote
audio problem with SDR on MacOS
Check the sample rate configuration in the software
you are using. Older Apple products used a hardware sample rate of 44.1 ksps, whereas newer Apple products all seem to use a hardware audio sample ...
- 13.3k
1
vote
Synchronizing HackRF Ones at a distance
Synchronizing clocks without wires usually involves radio. But since you're building a radio, "just use a radio" is probably not a useful solution.
Unfortunately, it's unlikely NTP (the most common ...
- 51.7k
1
vote
Fast TCP/IP radio modem on UHF band
I know there's actually people working on a system for that band. It'll be SDR-based.
There's no technical restriction that says you can't have a couple hundred kilobits per second in a couple ...
- 16k
1
vote
HACKRF_ERROR_NOT_FOUND
Your problem seems to involve USB permissions under Ubuntu, so perhaps your question would have been better-suited for askubuntu.com. But you probably didn't know that when you asked, so we shouldn't ...
- 9,192
Only top scored, non community-wiki answers of a minimum length are eligible