[Collins] 651S ! audio blanking

[Baruch Zilbershatz]

Hi to all!
I have this radio and when tuning te radio the audio goes blank.
I used to have another 651S 1 and there was no blanking on it .
I remember there was a modification  note but I cant seem to find it .
Can any body kindly help pse?
4z4rb Baruch
4z4rb at bezeqint.net

Baruch Zilbershatz 
4Z4-RB
Ha-Shibolim 18 Nitzanay-Oz,
Nitzanay-Oz 42836
ISRAEL

mobile   0528-753838