Search found 90 matches

by hotpaw2
Fri Jan 05, 2018 8:08 pm
Forum: Other SDR Devices
Topic: Airspy HF+ on a Raspberry Pi?
Replies: 4
Views: 5204

Re: Airspy HF+ on a Raspberry Pi?

The issue turned out to be that the permissions in the udev rules on the Raspberry Pi were different between default installations of the RTL-SDR library and the HF+ library. Changing either the user's group, or the device permissions, or the udev rules fixed the issue. After fixing this issue, the ...
by hotpaw2
Wed Jan 03, 2018 9:36 pm
Forum: Other SDR Devices
Topic: Airspy HF+ on a Raspberry Pi?
Replies: 4
Views: 5204

Airspy HF+ on a Raspberry Pi?

Has anyone got an Airspy HF+ working on a Raspberry Pi? I can compile and run SDR applications that link to libairspyhf on macOS. And libairspyhf builds and links without error on my Raspberry Pi 3. But the same code that runs on my Mac, reports no Airspy HF+ devices found on the Raspberry Pi. The c...
by hotpaw2
Sat Oct 21, 2017 1:27 am
Forum: RTL-SDR Discussion
Topic: How does the image rejection filter in the R820T(2) work?
Replies: 6
Views: 4521

Re: How does the image rejection filter in the R820T(2) work

So why is 65dB image rejection mentioned in the data sheet specification?
by hotpaw2
Mon Oct 09, 2017 5:48 pm
Forum: Troubleshooting Help
Topic: Command to rtl_tcp
Replies: 1
Views: 2276

Re: Command to rtl_tcp

There are both command-line options when starting rtl_tcp, and 5 byte parameterized-command messages that can get sent to the tcp socket/port when the socket is open (usually on port 1234). You can find source code to rtl_tcp here: https://github.com/osmocom/rtl-sdr/blob/master/src/rtl_tcp.c (Note t...
by hotpaw2
Sun Aug 20, 2017 11:46 pm
Forum: RTL-SDR Discussion
Topic: Weird interference and reception
Replies: 2
Views: 2857

Re: Weird interference and reception

Hi there, I am very confused as to what's going on here, I have a ground plane antenna designed fr air band My current location picks up the police fine, but not the tower, if I lean the antenna back 10cm it pick's up tower but not police. Also getting some kind of interference any help would be ap...
by hotpaw2
Mon Aug 07, 2017 4:53 pm
Forum: RTL-SDR Discussion
Topic: raspberry pi 2 make a lot of noise
Replies: 4
Views: 3831

Re: raspberry pi 2 make a lot of noise

Hi I asked in an other Forum but there was no solution. The Pi make a lot of noise! :o I cant use the Dongle for reception its insane how noisy it get and its impossible to receive anything. The Pi is in a Metal Case. :roll: I put the RTL-SDR dongle on a USB extension cable (with ferrite beads on i...
by hotpaw2
Thu Jul 20, 2017 4:05 pm
Forum: User Projects
Topic: Demodulate FSK
Replies: 6
Views: 17470

Re: Demodulate FSK

If you want to do this in code (your own program), and you know the bit or baud timing plus the two FSK frequencies, then two running Goertzel filters will work. They are roughly equivalent to narrow band-pass filters. Just take the difference of the two Goertzel filters magnitude outputs and look f...
by hotpaw2
Thu Jul 13, 2017 3:58 pm
Forum: RTL-SDR Discussion
Topic: I will make a SDR Spectrum software.
Replies: 3
Views: 2518

Re: I will make a SDR Spectrum software.

I will make a SDR Spectrum software. I want to know that RTL2832 only send RAW DATA(RF-signal digitalised)???? hent I just get these raw Rf stream data from USB (Yes, I will install driver for linux of this chip) and Then do FFT to these stream, Then I will get spectrum. You have the basic idea. An...
by hotpaw2
Fri Jun 23, 2017 9:51 am
Forum: RTL-SDR Discussion
Topic: Not very successfull with SDR - Advice
Replies: 50
Views: 24113

Re: Not very successfull with SDR - Advice

If you haven't already, you might want to remove the Ham-it-up converter so you can debug each component (converter versus RTL-SDR) separately. After removing the converter, set the offset in your software to zero. I'm using a discone on a long coax, with no LNA, and can receive local aviation band ...
by hotpaw2
Wed Jun 21, 2017 6:25 pm
Forum: RTL-SDR Discussion
Topic: Not very successfull with SDR - Advice
Replies: 50
Views: 24113

Re: Not very successfull with SDR - Advice

An LNA won't help if the reason for lack of success is due to a high RF noise floor. An LNA (without an appropriate bandpass or notch filter) amplifies the noise just as much as the signal, so would be no help whatsoever if the problem is RF noise at the antenna. One solution might be to use, not an...