This may be way too deep, but I'll throw it out for someone... Looking at swapping an older King 197 Comm for a free KY 97A (known good too).
Looking at the pin out differences...
Looks like the old radio had a built in dim sensor, while the KY 97A has pin A "Dim Select" and pin B for +14 V lighting input. So, OK, cool it can track panel dimmer lighting. However... I don't have a simple rheostat, I have a PWM dimmer circuit. [Buzzword alert: PWM = pulse width modulation, basically the dimmer dims by turning on and off many times per second, varying the on vs. off time to control brightness.] Similar to https://www.aircraftspruce.com/catal.../pwmdimmer.php
- but actually home built. Has anyone used a PWM dimmer with a KY 97A?
I'd hate to put this in and discover I can't get the dimming to work.
thanks in advance for helpful info.