The Y1506  (P/N 154-0499-00) is an SHF cermet triode vacuum tube used in the 1L20 oscillators (2×).

It was replaced by the Y1641 in 1967.

Some instruments using part Y1506

Instrument Manufacturer Class Model Description Introduced
1L20 Tektronix Plug-in 1L20 4.2 GHz Spectrum Analyzer plug-in 1965
drawing from 050-0348-00.pdf