In my case I found two possible solutions, which worked for me.
1: For the unrecognized "Radio Tune" if you change the Speech Recongnition, it will work again.. dont know why..., i have changed speech USA to speech UK, and everything go fine..( I am not native English speakers)
2: When you say 127.0 but you get 127.20 or different..
Try to say only "127 decimal" same for alls frequencys with .0
So if i want 133.055 , i have to say : 133 decimal 55
But 133.550 you need to say decimal five five zero.
For me it is working like this, so I have adapted.
There's some mores adaptations, like if you say "radar range twenty five" or "radar range one hundred", is fine... you get range 25, and range 100
BUT if you say "radar range fifty" he go to radar range 25..., you must to say "radar range five zero" to get range 50...,
:doh::megalol: