Erik PE1RQF offered to do measurements on his Baofeng BF-F9, before and after changing default squelch levels with Chirp. As expected after field tests, the differences are substantial. Here they are:
VHF (default settings, thresholds in dBm)
| SQ Set | BF-F9 setting | Threshold |
| 1 | 40 | -124,6 |
| 2 | 41 | -123,8 |
| 3 | 42 | -122,2 |
| 4 | 43 | -120,8 |
| 5 | 44 | -120,6 |
| 6 | 45 | -119,9 |
| 7 | 46 | -119,4 |
| 8 | 47 | -118,8 |
| 9 | 48 | -118,4 |
VHF, Default thresholds
VHF (new settings, thresholds in dBm)
| SQ Set | BF-F9 setting | Threshold |
| 1 | 24 | -130,4 |
| 2 | 29 | -131,4 |
| 3 | 34 | -130,9 |
| 4 | 39 | -129,6 |
| 5 | 44 | -125,5 |
| 6 | 49 | -120,1 |
| 7 | 54 | -115,3 |
| 8 | 59 | -110,2 |
| 9 | 64 | -105,1 |
VHF, new thresholds
UHF (default settings, thresholds in dBm)
| SQ Set | BF-F9 setting | Threshold |
| 1 | 29 | -140,1 |
| 2 | 30 | -130,9 |
| 3 | 31 | -129,0 |
| 4 | 32 | -127,4 |
| 5 | 33 | -126,6 |
| 6 | 34 | -125,4 |
| 7 | 35 | -123,8 |
| 8 | 36 | -123,0 |
| 9 | 37 | -121,6 |
UHF, default thresholds
UHF (new settings, thresholds in dBm)
| SQ Set | BF-F9 setting | Threshold |
| 1 | 24 | -133,1 |
| 2 | 29 | -133,1 |
| 3 | 34 | -125,6 |
| 4 | 39 | -120,7 |
| 5 | 44 | -114,1 |
| 6 | 49 | -108,6 |
| 7 | 54 | -103,6 |
| 8 | 59 | -97,6 |
| 9 | 64 | -93,7 |
UHF, new thresholds
Ham Radio Blog PD0AC 
My thanks to both you and Erik.
I know it made a big difference with my Baofengs.
It’s great to see the actual differences in black and white.
Many many thanks.
John
http://www.miklor.com/COM/UV_Squelch.php
Maybe I did the right thing by not touching the squelch, but then I don’t have chirp either. I did it manually.
The lowest closed setting for both my UV and GT is 1 so I have 1 in spot number 2 and so on up the line by 5’s until 40 then I jump to 10’s.. Works for me!
Great article.
Now I feel my GT-3 as a true radio dealing with squelch wise
73
Alberto YV3AR