This is list of common issues when using the PITS shield with RPi.
It's transmitting but I can't decode the RTTY
If you are seeing the correct 2 bands but are getting gobbledygook (random symbols) then try these things.
Increase the volume output of SDRSharp. Even though it is a virtual audio device it still has volume, so set that high if you can't get anything
Set the Receive filter bandwidth to 300 (or auto)
No RTTY transmission
The LoRa packet is transmitted but there is no RTTY transmission even though it is logged out as transmitting.
Check the program you are using. The lastest version of LoRaTracker no longer sends out RTTY via radio and instead does it via audio instead (this is to test the LoRa decoding capabilities of the payload for receiving)
There is a dedicated program for RTTY transmission
RTTY but it can't be decoded
If it sounds like RTTY (you need have experience to know that) but you can't decode the packets
This is due to the fact the settings you are using is incorrect, try changing the baud rate or bit numbers
If you find out that the baud rate doesn't match up with the board comments then it could be that you have flashed the arduino chip at wrong frequency i.e. 8mhz for a 16mhz chip