HP 85108, System Manual

Page: 105 / 136

A2 Pulse IF Mux Board. The pulsed-RF IF signals trav el through coaxial cables to the input
of the A2 Pulse IF Mux b oard. Firm w are con trolled switches select either b1 or b2 test
IF signals for output at J2, and either a1 or a2 reference IF signal for output at J6. An
additional function of the A2 pulse IF Mux b oard allo ws connection of a 19.9 MHz calibration
signal in to the test and reference IF signal paths during IF calibration.
Pulse Detector Boards. The test IF signal con tinues from A2J2 to A3J1 of the A3 Pulse
detector b oard. The reference IF signal con tinues from A2J6 to A4J1 of the A4 Pulse detector
b oard. The detectors on the A3 and A4 b oards generate X and Y v ector signals from the test
and reference IF signals. A 20 MHz reference signal for the detectors is supplied b y the A6
clo c k b oard. The X output is at J2 and the Y output at J3 on eac h b oard.
A16 Remote Application / Pulse Track & Hold Board. The X and Y test signals en ter A16 at
J3 and J4 resp ectiv ely . The X and Y reference signals en ter at J1 and J2 resp ectiv ely . The
signals are fed in to track and hold circuits. The outputs of the T/H circuits are sen t on to
the A17 Sample/hold b oard m ultiplexer circuits. A t the m ultiplexer circuits the signal paths
con v erge to b e the same as the normal BW, nonpulsed-RF paths.
HP 85108 IF/Detector Option 008
Pulsed-RF IF P ath Troubleshooting Flo w chart
The troublesho oting o w c hart ( Figure 6-6 ) is used when the problem has b een isolated to
the IF/Detector. If the problem is presen t during b oth normal BW and wide BW mo des
of op eration, do not use this o w c hart, instead refer to the troublesho oting section of the
HP 8510C service man ual. This o w c hart addresses only the b oards and cables unique to
pulsed-RF op eration.
System Service and Troubleshooting 6-13