[hpsdr] Multi tracking Notch Filter no longer works

[Pierre GROS (gmail)]

Dear all, , dear François
I finally figured out how to use the multi-notch filter with version  
openHPSDR mRX PS v 3.4.9
To make for easy start , go on broadcast band and use an AM station with 
SSB mode . the carrier will be easy to spot and hear .
Turn on the MNF button . it becomes coloured
Menu/ DSP/MNF
Type ADD first , this must be done first (important , that was my 
problem , wanting to "add" at the end instead of at the start  )
Type frequency of carrier to eliminate in "Center frequency"
to find the carrier frequency without detuning your QSO you can use the 
panadapter and navigate with the mouse looking at the frequency display 
in blue above the Pan controls , and type the frequency in the box .
if you are right on the carrier , you can alternately use "VFOA"
Type width of filtering in "width"
ENTER
The carrier is eliminated
Voila !
And you congtinue with ADD etc... for the next notches to add
Don't forget to delete the notches after your QSO if the carrier is not 
a fixed nuisance , but just temporary QRM


Best regards
Pierre Gros F6IES