How to disable the warning "out coverage" tone

[Yealink Support]

Hi Walter,

Do you mean a verification tone with repeater?

To find the best possible location for the repeater, you may need to try various locations.
Place a call and walk around with the handset to determine the base station’s coverage
area. The verification tone allows you to easily check the extent of the repeater’s
coverage area. The tone is audible on the handset during a call.
To activate the verification tone on the repeater:
1. Switch off the repeater ( disconnect the power adapter).
2. Switch it on for 1 to 5 seconds and switch it off again.
3. Switch it on again. The LED indicator on the repeater flashes slowly.
4. Switch it off again.
5. Switch it on again.
The verification tone is then activated.

Place a call using the handset to check whether the handset is working in the extended
area of the repeater. If the call is successfully handled by the repeater, you can hear the
verification tone from the handset every few seconds.
To deactivate the verification tone, repeat the above steps.

You can also refer to more details in below link.
http://www.yealink.com/Upload/W52P/V40/Y...0Guide.pdf