Hi Terry:
You might want to check out or call Bennett Avionics for some answers
https://www.bennettavionics.com/ky-197a-comm-transceiver/From their website:
The King KY-197A is an update to the popular 14 volt King KY-197 COMM. The KY-197A offers a number of new features over the KY-197, including:
760 COMM channel capability (instead of 720)
Remote push button frequency flip-flop capability for greater convenience
9 frequency memory channels stored in non-volatile memory (no power is needed to retain the memory settings)
Memory channels may be remotely called up and scrolled
Audio leveling feature removes some of the variation between loud and quiet transmissions
The KY-197A retains these KY-197 features:
Designed for aircraft with 14 volt electrical systems
Standard bright and easy-to-read King gas discharge display
Simultaneous digital display of both active and standby frequencies
Push button frequency flip-flop
10 watts transmit power
TSO'd
Hope this helps