If Signature; A5 If Assembly - Agilent Technologies 8564EC Service Manual

IF Section

A5 IF Assembly

For troubleshooting, it is recommended that you use an active probe,
CAUTION
such as an 85024A, and another spectrum analyzer. If an 1120A active
probe is being used with a spectrum analyzer having dc-coupled inputs,
such as the 8566A/B, 8569A/B and the 8562A/B, either set the active
probe for an ac-coupled output or use a dc-blocking capacitor between
the active probe and the spectrum analyzer input.
Do not short control voltages to ground. These voltages are not
CAUTION
short-circuit protected. DACs damaged by shorting these voltages
might not fail until several weeks after the shorting takes place.
Do not short power supply voltages to ground. The 8564EC or
8565EC spectrum analyzer power supply current limiting cannot
protect the resistors in series with the power supply.
Some transistors have collectors connected to the case. Electrical
NOTE
connection of the case to the collector might not be reliable, making
collector voltage measurements on the transistor case unreliable.

IF Signature

1. Disconnect W27 (coax 3) from A5J5.
2. Connect an SMB tee to A5J5, using a short coaxial cable with SMB
3. Connect one output of the tee to cable W27 (coax 3).
4. Connect an 85024A active probe, with a 10:1 divider installed, to the
5. Connect the output (type N connector) of the active probe to the
6. Connect the probe power cable to the 8564EC or 8565EC
456
connectors.
other output of the tee.
input of the 8566A/B spectrum analyzer.
spectrum analyzer front panel PROBE POWER connector (you may
need to use a probe power extension cable, 10131B).
Chapter 9