Hi Karl,
Many thanks for the info. I suspected the binary might work but was not sure.
Anyway, building gqrx on Raspbian Stretch should be easier now and the
strategy I would recommend is as follows:
1. Install gnuradio-dev from Raspbian repository
2. Install the driver libraries from source - some might be OK from repository
3. Install gr-osmosdr (or gr-osmosdr-gqrx) from source
4. Install gqrx from source
Before running gqrx make sure to run volk_profile (available in libvolk-bin)
I'd be happy to assist if anyone wants to give it a go :)
Alex