Lothar's TL;DR on SDR selection for AIS, ADS-B, UAT, ACARS, VDL2 and Sondes

Since TBG wanted to pin this in the Airframes.io Discord server, I thought I would post this updated version of my rant here.
Lothar’s general advice is:

  • AVOID ALL plastic cased SDRs.
  • FAVOR any SDR that uses the SKY7510 LNA, as it is hands down the lowest NF of any common LNA chip.
  • FAVOR SDRs with Genuine Taisaw SAW filters for 1090.
  • FAVOR LNA>filter over Filter>LNA SDRs topology for 1090 SDRs (unless you are in a rough high RF environment, where you MUST use an unfiltered orange stick and a cavity filter.
  • ADD heat coupling putty pads (NOT adhesive foam thermal heat sink attachment pads) between the underside of the SDR PCB and the metal case. I use Gelid Solutions GP-Extreme 2.0mm Thermal Pads, available at Amazon, DigiKey, Mouser etc.

Happy Feeding!

This is one of the most solid tl;dr’s for SDR’s (filter and LNA variety) ever!!
Thanks so much.
Going to be able to refer a bunch of people that ask this.
Wish we could put it in a LLM (large language model) for AI to answer this FAQ!

Hope you don’t mind, I did a quick format edit of your post for readability.

Also, where do we get the putty pads (not adhesive foam) from? I feel that all the Pi heatsink kits come with foam, but am not sure what to google/amazon for the putty.