rtl-sdr.com

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/

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...

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.

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.

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,

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...

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...

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.

Has any one tapped the output of the R820T2 to use an RTL-SDR as a downconverter from VHF or UHF to HF? That way one could use an HF-only receiver or direct-sampling SDR to receive higher frequencies than the receiver supports. For instance, one could use an HF SDR with a 16-bit ADC instead of using...

You could try looping various cords and cables connected to your PC through a ferrite toroid, one at a time, and see which, if any, connector is leaking the RFI.