It is possible to change the TRANSMIT settings of an existing channel by making the change then re-saving the data. It is NEVER possible to change any of the RECEIVE settings without deleting the entire channel [menu, 28] and starting over.
This radio saves the receive data and the transmit data separately in the same channel number. Everything about the receive conditions must be set and saved first (which is all you need for a basic simplex channel with no Tx tone etc.)
All TRANSMIT settings (including any tone, code or having the Tx frequency showing in the display) must be set and saved separately to create a complete channel. If you were to save updated data to that same channel a second or third time, you would ONLY replace the previous TRANSMIT data without ever altering the saved RECEIVE data.
If the RECEIVE channel is improperly programmed, the channel must be totally deleted and reprogrammed.
Important note:
So, it really is possible to change the Tx tone, but it is quite a bit more complicated than just changing the menu setting. You need to:
Change the menu setting
Ensure that the TRANSMIT frequency is displayed in the top display
Save the complete transmit data back to the same channel.
Most people forget to have the transmit frequency displayed and save the Transmit data with the receive frequency displayed. That will accidentally create a simplex channel.
The radio acts much like a computer… it does what you tell it to do, not necessarily what you want it to do.