BER Tuning for HotSpots
Many Hotspot devices use “Pi-Star” as the base operating system. For some Hotspots setting the RX offset or TX offset based on the information found on the bottom of the modem board still leaves the bit error rate high.

Start with the Hotspot Offset Calibration site listed below. K9NPX has detailed the procedure pretty well. This is the easiest way to make sure your BER is at rock bottom… Check it out.
Hotspot Offset Calibration http://www.k9npx.com/2019/02/hotspot-offset-calibration.html
Another good link that details the process of adjusting your BER. Read the information on the website then watch the video or it will be really confusing. Don’t worry if you can’t hit the magical “0”… Bit Error Rates below 0.5 work just fine (the lower the better). This is a great site for adjusting BER. Check it out first.
*Note: The MMDVMCAL program he is compiling in the video is already built into all the new versions of Pi-Star so that step can be skipped.