I have made some progress.
A new build of Pothosware was uploaded by Josh on Monday 12/3/18 that replaces 6/2/18. I installed this and things seem to have improved marginally.
CubicSDR - Will now work - I can successfully demodulate FM signals in the central 100KHz. If I increase the sample rate the spectrum is zero except over the central 100KHz. It seems like there is a filter in the FPGA rejecting wider band signals.
SDRv3 - Still not working with the mini - but works with the SDR-USB.
GQRX(Windows - Pothos build) - Not working at all
GQRX(Ubuntu) fails and shos the following errors:-
[ERROR] SetFrequencyCGEN(80 MHz) failed:
INT: 63 FRAC: 0 DIV_OUTCH_CGEN: 15
VCO: 2560 MHz RefClk: 40 MHz
TuneVCO(CGEN) - VCO too low
[ERROR] SetFrequencyCGEN(80 MHz) failed:
INT: 63 FRAC: 0 DIV_OUTCH_CGEN: 15
VCO: 2560 MHz RefClk: 40 MHz
TuneVCO(CGEN) - VCO too low
[ERROR] MCU working too long 4
[ERROR] setBandwidth(Rx, 0, 30 MHz) Failed - SetFrequencyCGEN(80 MHz) failed:
INT: 63 FRAC: 0 DIV_OUTCH_CGEN: 15
VCO: 2560 MHz RefClk: 40 MHz
TuneVCO(CGEN) - VCO too low
Pothos Flow - Will not work and returns the following errors
[13:14:42.830000] SoapySDR: Make connection: 'LimeSDR Mini [USB 3] 1D3A0BF36xxxxx'
[13:14:43.455000] SoapySDR: Reference clock 40.00 MHz
[13:14:43.470000] SoapySDR: Device name: LimeSDR-Mini
[13:14:43.470000] SoapySDR: Reference: 4e+07 MHz
[13:14:44.469000] SoapySDR: LMS7002M calibration values caching Disable
[13:14:44.500000] SoapySDR: SetFrequencyCGEN(80 MHz) failed
[13:14:44.547000] SoapySDR: SetFrequencyCGEN(128 MHz) failed
GNUradio Companion - using OSMOCOM driver - runs, but the spectrum looks wrong and the following errors are returned.
Executing: C:\Python27\python.exe -u C:\Users\hagst\Documents\top_block.py
Error: EnvironmentError: OSError: LoadLibrary failed to load "C:\Program Files\PothosSDR\lib\uhd\modules\umtrx.dll"
gr-osmosdr v0.1.4-98-gc653754d (0.1.5git) gnuradio 3.7.11.1
built-in source types: file osmosdr fcd rtl rtl_tcp uhd miri hackrf bladerf airspy soapy redpitaya
[INFO] Make connection: 'LimeSDR Mini [USB 3] 1D3A0BF36xxxxx'
[INFO] Reference clock 40.00 MHz
[INFO] Device name: LimeSDR-Mini
[INFO] Reference: 4e+07 MHz
[INFO] LMS7002M calibration values caching Disable
e[1me[31m[ERROR] SetFrequencyCGEN(80 MHz) failede[0m
e[1me[31m[ERROR] SetFrequencyCGEN(160 MHz) failede[0m
[INFO] RX LPF configured
gr::pagesize: no info; setting pagesize = 4096
[INFO] Rx calibration finished
Seems like the issue definitely resides in the SetFrequencyCGEN(80 MHz) routine.