Sorry we do not know exactly what this is. We welcome suggestions. Looks to be some type of RF amplifier, or transmitter (or transceiver?) as it looks to have 3 RF power transistors and a Yasuda XX-220P coaxial relay. Schematic shown we found online and shows same model # and brand and is provided in this listing for your reference only (may or may not be same revision etc, you can zoom in and compare) Thks board came from a hamfest (ham radio show) in a box lot of surplus electronics, most of which were good, but this looks to have been removed from a housing/heatsink so no idea if it works, or has issues, or was a good spare or a pulled dud, selling as you see it for parts. Nothing looks to be visibly damaged nor burnt. All sales final sold as is