Yup. Also, power RF amps are often still today based on (a type of) tubes.
Tektronix had some tube-based active probes with up to 850MHz of bandwidth, for use with equivalent-time sampling oscilloscopes in the early 1960's. The first real-time transistorized scope able to use that bandwidth didn't come along until the late 1970's.
Tektronix had some tube-based active probes with up to 850MHz of bandwidth, for use with equivalent-time sampling oscilloscopes in the early 1960's. The first real-time transistorized scope able to use that bandwidth didn't come along until the late 1970's.