Which units will the VHF-22C 8.33 kHz comm radio directly replace?
The VHF-22C is only a direct replacement for the VHF-22A 25 kHz comm. The VHF-22C is not a direct replacement for the VHF-20A or VHF-21A radios as they have different mating connector styles. The VHF-22D is a direct replacement for the VHF-22B.