Hi all,
I want to swap my actual R820T dongle with a R820T2 model on my PiAware installation.
Question : does something has to be (re)initialized or modified in one or other part of the software ?
Thanks a lot for your feedback.
Executive summary: Power it down, do the swap, and bring it back up again. You shouldn’t have to touch any of the software.
Discussion:
The answer is a definitive, resounding, “it depends.” You shouldn’t have to change any of the software.
If you have an older Pi model B, you’re best off powering things down to make the swap as making USB changes usually causes these to reboot. More modern Pi systems, such as the B+ and the Pi 2 have power subsystems which can survive a USB hot-plug.
On the software side, Obj’s Dump1090-mutability is designed to support hot SDR swaps. The stock Dump1090 program I don’t believe will do this.
Which circles back to the quick and safe route – power down, do the swap, power up again.
–bob k6rtm
I do have a B+ but I’ll follow your recommendations 
Thank you Bob.
Springtime greetings from BRU to California 
I have a B+ “live” and a Pi2 “Dev” system. I have hot swapped my R820T and R820T2 between both several times with no ill effects. With my config, the R820T outperforms the R820T2. You should verify that the PPM is not different and restart Dump1090 if you need to adjust the settings between dongles. My PPM corrections are not too far off from each other at 55 and 63. But for troubleshooting, I will sometimes hot swap without adjusting PPM or restarting.
Cheers!
LitterBug