WR501
The Tektronix WR 501 is a 16-channel word recognizer with delay, packaged in a TM 500 plug-in. The WR 501 can provide a trigger signal for an oscilloscope or provide a trigger signal and data acquisition for the LA501 Logic Analyzer.
Note that DL15 and DL115, the 24 pin delay lines that fit in the sockets on each board are only found on units that were interconnected to an LA 501. The empty socket for DL15 is visible in the pictures below, on the A1 daughter board. The socket for DL115 is on the board underneath A1, on the A2 main board. They are unnecessary if you are using the WR501 to trigger a scope.
These ECL delay lines, pn 119-0775-00, 10 ns, 100 Ω, can be found in the 7D01 logic analyzer plugin for the 7000-series scopes.
