Search found 105 matches

by hotpaw2
Fri Feb 23, 2018 4:17 pm
Forum: Antennas
Topic: Grounding of Active Antennas Like The Mini-Whip
Replies: 6
Views: 7215

Re: Grounding of Active Antennas Like The Mini-Whip

A mini-whip likely uses either the outer coax shield or the mast as part of the antenna (the counterpose), so it likely doesn't matter as long as both are far away from noise sources (e.g. up high).
by hotpaw2
Thu Feb 22, 2018 7:28 am
Forum: Other SDR Devices
Topic: Airspy HF+ on a Raspberry Pi?
Replies: 4
Views: 5663

Re: Airspy HF+ on a Raspberry Pi?

I just posted source code on github of a very simple rtl_tcp server for the AirSpy HF+: hfp_tcp_server.c https://gist.github.com/hotpaw2/8c720c324ac0794aa7bf98c505eb61d5 This allows me to develop SDR clients for both the RTL-SDR and the HF+ using the same rtl_tcp protocol for both (except for the di...
by hotpaw2
Thu Feb 15, 2018 9:55 pm
Forum: RTL-SDR Discussion
Topic: Raw digital output from usb dongle
Replies: 8
Views: 6195

Re: Raw digital output from usb dongle

How does one determine how much PLL settling time is needed after each frequency jump? I assume the IQ data is mostly garbage until after the PLL + internal filter settling time.
by hotpaw2
Wed Jan 31, 2018 6:10 pm
Forum: Troubleshooting Help
Topic: NooElec NESDR SMArt - Error: Cannot access RTL device
Replies: 4
Views: 4558

Re: NooElec NESDR SMArt - Error: Cannot access RTL device

I also helps to have more than one RTL device available to test, to see if the problem is with software or with hardware. I had one of the smaller NooElec devices get hot and fail.
by hotpaw2
Mon Jan 29, 2018 9:04 pm
Forum: RTL-SDR Discussion
Topic: Looking for SDR software with plugins
Replies: 3
Views: 2065

Re: Looking for SDR software with plugins

On my Raspberry Pi, running a Linux variant, I use rtl_tcp to connect to the RTL-SDR, and plug my own DSP software (filters, demodulators, spectrum visualization, etc.) directly into the tcp-ip socket IQ data stream from rtl_tcp, which is an extremely simple interface to the raw IQ data.
by hotpaw2
Fri Jan 05, 2018 8:08 pm
Forum: Other SDR Devices
Topic: Airspy HF+ on a Raspberry Pi?
Replies: 4
Views: 5663

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: 5663

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: 5176

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: 2568

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: 3248

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...