Does anybody have data on the CEX “Local Oscillator Frequency Extension” band ranges for the NS73M? I can’t seem to find anything in the data sheet —but then I have been known to miss stuff like that before.
I have the chip running at 97.3 with Register 8 set to band 2 per the example(s) and it works fine around that frequency, but when I stray to far things stop working.
My assumption is that the bands are divided over the FM range and that I could probably just make some arbitrary bounds to get things working, but it would be nice to have the actual numbers.
The example flow chart in the application note (Set CEX Routine, page 22) shows how to set up the registers, but does not give the band ranges.
As a matter of interest; I have an eight pin 12F683 PIC driving the NS73M with frequency entry done by a simple sequence of button presses. This gives a very low component count. The PIC EEPROM stores last frequency for use when the system is turned on.