Agilent Technologies 85309B, Manual, Page: 25 / 76

Service Guide 85309-90082 2-5
LO/IF Distribution Unit Operating Information
85309B 85309B Rear Panel Features
85309B Rear Panel Features
CAUTION The 85309B contains static sensitive devices. Never touch the center conductor of any
connector. When cleaning connectors, wear a grounded wrist strap.
Figure 2-4 shows 85309B Option 402 rear panel features, including two additional test channels and an
active J15 “High/Low Band Select” port. The rear panel on your 85309B model may not include all of the
ports shown. Note that the connectors are arranged in the following groups:
• Ref Mixer
• Test Mixers
• LO Source
• Receiver
• J7 and J8 are separate connectors that function as jumpers for the IF path or as ports for non-diplexed
test mixers of the LO/IF unit.
• (Option 40x only) J15 is a separate connector that allows external control of the HIGH/LOW BAND
SELECT feature.
Figure 2-4 85309B Rear Panel Features (Option 402)
Ref Mixer Connector Group
The three connectors in this group, J2 REFERENCE LO OUT, J4 REFERENCE IF IN, and J5 REFERENCE DET
IN, are connected to the reference mixer. Besides the RF, LO, and IF ports, the reference mixer has an
additional DETECTOR output.
J2 REFERENCE LO OUT. This port sends the local oscillator signal to the reference mixer.
J4 REFERENCE IF IN. This port receives the IF from the reference mixer. The 85309B amplifies this signal
and sends it to the receiver using the J10 REFERENCE IF OUT connector.
J5 REFERENCE DET IN. A power detector in the reference mixer measures incoming LO power and outputs
a proportional voltage. This voltage enters the 85309B through this connector, and is used to level the LO