The 154-XXXX-XX (previously 154-XXX) part number category was for electron tubes including cathode-ray tubes (CRT). These documents are useful for identifying and finding vacuum tubes for Tektronix instruments. They do not include CRTs.
Vendor Nomenclature to Tektronix Part Number Index
Tektronix Tube Cross Reference
The 157-XXXX-XX (previously 157-XXX) part number category was for matched or selected tubes. This document describes the procedure for these part numbers.
157- Matched and Selected Tubes
The Replaceable Parts Registry (RPR) lists part numbers where used and is useful for finding a donor instrument for tubes, especially CRTs. We have scanned the Replaceable Parts Registry for the 154- prefix and it is hosted on TekWiki (external site).
Tektronix RPR for 154- Vacuum Tubes including CRTs (external site)