Silver labs 5212
Brochure 1969
No information yet. It measures frequency from 2400-4000MHz
According the former owner who owned it for many years it can handle a few Watt of RF. The diode inside is the limmiting factor. But I have not opened it to search a datasheet. The N connectors are in/out. You can connect it between transmitter and dummyload or antenna and the bnc gives a rectified signal. Inside is a cavity that resonates at the frequency you dial. Like a dipper used as fieldstrenght meter. The voltage wil be maximum at resonance.