In article ,
Fred McKenzie wrote:

This presents an additional problem with C4FM channels that also had
tone settings programmed in FM mode prior to selecting the C4FM mode.
They will each need to be individually re-programmed and saved over the
old channel data. Otherwise the AMS feature may be receive-only.

If anyone is interested, here is a method of making minor changes to an
FT-991 channel contents. If you have "TAG" text set for a channel, it
will be lost. Make note of it ahead of time.

1. Set FT-991 to channel of interest

2. Press A=B

3. Press V/M

4. Press A/B

5. Make changes

6. Write data back to channel of interest.

I use this method in fixing of Tone Encoder for Fusion AMS:

5a. Change Mode to FM

5b. Set tone and encoder for channel of interest

5c Change Mode back to C4FM

This saved me a lot of time after updating firmware the last two times!

Fred
K4DII