Search found 178 matches

by hotpaw2
Wed May 12, 2021 2:39 pm
Forum: RTL-SDR Discussion
Topic: Cannot get a good FM signal
Replies: 2
Views: 217

Re: Cannot get a good FM signal

It could be RF noise from the computer getting into either the SDR or the antenna feed line.
by hotpaw2
Mon May 10, 2021 12:19 am
Forum: Troubleshooting Help
Topic: Incoherent spikes in direct sampling mode.
Replies: 1
Views: 208

Re: Incoherent spikes in direct sampling mode.

Those could be noise spikes caused by harmonics from a nearby 100 kHz power supply or other noise generator (solar panels, LED lights, USB chargers, etc.). Try running your RTL-SDR from a portable laptop/notebook computer on a picnic table far (1000's of meters) away from the nearest buildings, sola...
by hotpaw2
Wed Apr 21, 2021 3:03 pm
Forum: Off-Topic
Topic: Wide spectrum analyzer
Replies: 1
Views: 1010

Re: Wide spectrum analyzer

The TinySA spectrum analyzer goes from 100 kHz to 960 MHz, with over 300 MHz of bandwidth. Seems to be available from various vendors for between $50 to $100. https://www.tinysa.org/wiki/
by hotpaw2
Tue Apr 20, 2021 4:01 pm
Forum: Other SDR Devices
Topic: how good is Luowave's "USRP LW 1"?
Replies: 3
Views: 2138

Re: how good is Luowave's "USRP LW 1"?

For over $200 (USD) less, you can get a direct sampling SDR with slightly higher 76 MHz sample rate 12-bit ADC, and a much faster Gigabit ethernet connection. It's the Hermes Lite 2. Several hundred built. I have a couple. Component quality from Makerfabs seems excellent. If you want more bits for a...
by hotpaw2
Fri Apr 16, 2021 5:21 am
Forum: RTL-SDR Discussion
Topic: How to develop own software for scanning frequencies and checking for radio activity
Replies: 1
Views: 270

Re: How to develop own software for scanning frequencies and checking for radio activity

There are several tutorials on writing programs for the RTL-SDR.
Here's one for Python, mentioned on this site:
https://www.rtl-sdr.com/developing-your ... th-python/
Google will find others.
by hotpaw2
Mon Apr 12, 2021 6:07 pm
Forum: RTL-SDR Discussion
Topic: Why do I need an SDR?
Replies: 3
Views: 1077

Re: Why do I need an SDR?

Depends on if you want to receive local stuff on your own antenna, and not depend on the internet working or someone else's server to be up and running and not busy.
by hotpaw2
Sat Apr 10, 2021 6:12 pm
Forum: RTL-SDR Discussion
Topic: SDR-RTL for longwave and mediumwave
Replies: 3
Views: 632

Re: SDR-RTL for longwave and mediumwave

An RTL-SDR V.3 in Direct Sampling mode might work. But if you can afford to pay for a more expensive SDR, consider the Airspy HF+ Discovery or SDRPlay RSPdx for more dynamic range, less likelihood of overload, and perhaps better sensitivity in the LF and MF frequency ranges,
by hotpaw2
Thu Mar 04, 2021 6:37 pm
Forum: RTL-SDR Discussion
Topic: Why Can't I Grasp This?!?
Replies: 6
Views: 787

Re: Why Can't I Grasp This?!?

The RTL-SDR operating receive frequency has to be set by software. That receive frequency is not stored in the RTL-SDR when power is removed, but has to be set by software each time the unit is started. However, some RTL-SDR units have a band-pass filter in front of the tuner, set to certain aviatio...
by hotpaw2
Mon Feb 22, 2021 5:58 pm
Forum: Antennas
Topic: Best antenna for HF
Replies: 8
Views: 2326

Re: Best antenna for HF

Check the noise floor at your antenna location. If you can see a raised noise floor on your SDR's spectrum display when you attach a small loop antenna, then a larger quarter or half wavelength antenna won't really improve your reception. Physics says that not only will a better antenna pick up more...
by hotpaw2
Mon Feb 15, 2021 7:07 pm
Forum: User Projects
Topic: A potential work-around for multiple RTL devices with their own spyserver
Replies: 5
Views: 4884

Re: A potential work-around for multiple RTL devices with their own spyserver

My overly-simplified method of running multiple SDR dongles without any device ID issues is to use a separate Raspberry Pi for each USB dongle. I co-locate the Pi's and SDRs near my antenna distribution panel. Then I run all the networked Pi's remotely from a Mac.