NBFM on 2m: de-emphasis values too fast

Hi All,

My KiwiSDR system with a 2m converter is used by the local club for FM nets. The audio is rather "harsh" and I note the FM de-emphasis time constants are 50us and 75us. These could usefully be 500us and 750us, as it seems unlikely anyone will use KiwiSDR for FM broadcast reception?

Digging into the code, the file rx/rx_sound.cpp has this at line 655:

double T1 = (de_emp == 1)? 0.000075 : 0.000050;

If those two numbers were changed to be 10x larger, it should make NBFM audio much smoother. The drop-down menu values would need to be changed to reflect it too.

73, Rob


Sign In or Register to comment.