OK, many thanks. I found the missing link that I needed. I followed the instructions here - https://github.com/pothosware/pothos/wiki/Ubuntu & was finally able to find the source and sink blocks in Pothos, see and connect them to the board. I don’t know what was missing in the GNU Radio Companion GRC setup, but will address that later. I also found the NBFM example at Working NBFM transceiver on GNU radio I don’t know why that one is so hard to find.
