RTL SDR and GRC3.7.8 problem: format error

Thanks Marcus yet again. In the past gr-osmosdr simply built seamlessly
along with gnuradio. Not this time. Don’t know why. My solution was
delete the gr-osmosdr files from the home directory and git clone from
Osmosdr website. The installation went smoothly and the RTL SDR
demos all run as expected. Just in time. And, I’ll not throttle again
against the Qt GUI block.

John Petrich

Ever since I updated to GRC3.7.8 none of my RTL SDR demos will run in
The error messages are the same: " list contains an invalid format".
Attached is the .grc file of a basic RTL Qt test flow graph authored
GRC3.7.8, and the .odt file with the complete error message. GRC
the RTL device, and cites format errors. Are others having this
with GRC3.7.8? I am anxious to resolve this problem because I have
scheduled a GRC presentation in the near future.

John Petrich

Marcus L.:

Did you re-build gr-osmosdr against 3.7.8? My suspicion is that the
gr-osmosdr you’re using is out-of-date with respect to the GR that is
calling it.

Also, you have a throttle block in between your hardware source, and
your Qt
GUI block. Don’t do that. You never need a throttle when you’re using
real hardware.