HP 85027A Service manual

OPERATING AND SERVICE MANUAL
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US P!avy Cahbrat!on Laboratory
Box 16 US Naval Air Station
FPO San Francisco 96654-2901
HP 85027A/B/C
DIRECTIONAL
BRIDGE
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Hewlett-Packard Company
Video Communications Division
5301 Stevens Creek Boulevard
PU Box 58059
Santa Clara, Cilifornia 95052-8059
408 246-4300
October 30, 1997
Jim Canton
Government-Industry Data Exchange Program
GIDEP Operations Center
Corona, California 91718-8000
Subject: COPYRIGHT RELEASE
Dear Mr. Canton:
Attached is the Copyright Document Release form you sentto me.
Inregards to thedocuments you have listed on your form thereproduced documents
must include the following legendand disclaimer:
‘Copyright - Hewlett-Packard Company (HF). Reproduced with HP permission.
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butnot limited to, the implied warranties of merchantability and fitness for a particular
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Please let me know, if you have any questions or if I can be of any furtherassistance.
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HEWLErr-PACKARD COMPANY
Dixie Luebcke
GIDEP Representative U7

MANUAL CHANGES
NOTE
Manual change supplements are revised as often as necessary to keep manuals as
current and accurate as possible. Hewlett-Packard recommends that you periodically
request the latest edition of this supplement. Free copies are available from all HP
offices. When requesting copies, quote the manual identification information from your
supplement, or the model number and print date from the title page of the manual.
MANUAL IDENTIFICATION
This supplement contains important information for correcting manual errors and for
adapting the manual to instruments containing improvements made after the printing of the
manual.
Two types of information are included:
UPDATES - APPLY TO ALL SERIAL NUMBERS.
NUMBERED CHANGES - UPDATES THAT ARE SERIAL NUMBER PREFIX RELATED.
The information is in the following order: UPDATES, NUMBERED CHANGES in sequen-
tial order with applicable illustrations as close as possible to each numbered change.
To use this supplement, make all UPDATES and all appropriate serial number related
CHANGES indicated in the following pages.
= NEW ITEM
UPDATES
Replace the following manual pages with the pages in this document (UPDATES):
General Information
1-6
~ Performance Tests
4-8
Adjustments
5-3
5-4
us r:~-:~’ C’~’~~
Box i~ ~
FF0 San Fra~~ £~3~
JANUARY 9, 1987
4 HEWLETT
I’ PACKARD
HP Number: HP 85027A/B/C
Date Printed: July 1985
Part Number: 85027-90001
Printed in U.S.A.

HP 85027A/B/C General Information
Table 1-1. Specifications
HP 85027A HP 85027B HP 85027C
Frequency Range (GHz)1
0.01 -1 8.0
0.01 -26.5 0.01 -1 8.0
Connector: Input Type
N (1) 3.5mm (f) - Type N (f)
Test Port APC-7 3.5mm (f) Type N (f)
Max. Input Power +23 dBm or
±l0volts
+23 dBm or
±l0volts
+23 dBm or
±l0volts
Directivity2
0.01 to 12.4 GHz >=4OdB >=40 dB >=36 dB
12.4 to 18.0 Ghz >=40 dB >=40 dB >=34 dB
18.Oto2O.OGhz — >=4OdB —
20.0to26.5GHz —
>=36dB —
Test Port Match2
0.01 to 8.4 GHz
>=23dB >=23dB >=23dB
8.4to12.4GHz >=l9dB >=l5dB >=l9dB
12.4 to 18.0 GHz > = 15 dB > =15 dB > = 15 dB
18.Oto2O.OGhz — >=l5dB
—
20.0 to 26.5 Ghz — >=11 dB —
it 50 MHz
to +7dBm input to bridge
0
0
Ui
E
E
S
3
2
I
U
-~
— Spe If Ice lons*
I .
2
—5 —10 — 15 —20 —‘5
Deite Power (dB) —~30
—~5 40
‘Measured
‘Ru at I vi
‘25’Ci5’C
Dynamic Power Accuracy
1-6
UPDATES APPLY TO ALL SERIALS

HP 85027A/B/C Performance Tests
Equipment HP
85027A HP 85027B HP 85027C
Sweep Oscillator HP 8350B HP 8350B
HP 835DB
RF plug-in HP 83592A HP 83595A HP 83592A
Scalar network analyzer HP 8757A HP 8757A HP 8757A
Cal. open/short 85021 -60021
85037-60001 85032-60001
50 ohm load 909A opt 012 909D
909A opt 012
Adapter* not req’d 85027-60002 1250-1 475
* A second directional bridge is required as a test instrument in addition to the directional bridge
under test. The adapters recommended are suitable for use with two similar bridges.
Procedure
1. Set up the equipment as shown in Figure 4-4, with the calibrated open connected to the test
directional bridge, not the directional bridge under test.
2. PRESET the analyzer. It should indicate that Input A is on Channel 1. Turn off Channel 2. The
Preset should also preset the sweep oscillator to a sweep time of 200 ms with 27.8 kHz
modulation on.
3. Set the sweep oscillator start and stop frequencies to correspond to the first band of
frequencies in the Performance Test Record (0.01 to 8.4 GHz).
4. Perform an open/short calibration and store it in memory.
5. Connect the directional bridge under test to the first directional bridge, test port to test port
with an adapter if necessary. Connect the 50 ohm load to the input port of the directional
bridge under test.
6. On the HP 8757A turn on the cursor and press the [MAX] softkeyto find the point of minimum
return loss (highest point) on the trace. Enter this value on the Performance Test Record.
7. Repeat steps 3 through 7 for each frequency band of interest.
8. If the test results (including uncertainties) are not within specifications -as indicated on the
Test Port Match Performance Test Record, refer to the Troubleshooting section of this
manual.
Table 4-2. Test Port Match Performance Test Record
HP 85027A HP 85027B HP 85027C
Frequency Spec. Test Spec. Test Spec. Test
Band (GHz) Result Result Result
0.01-8.4 > =23 dB ______ > =23 dB ______ > =23 dB _______
8.4-12.4 >=l9dB _____ >=l5dB _____ >=19dB _______
12.4-18.0 >=l5dB _____ >=l5dB _____ >=l5dB _______
18.0-20.0 — >=l5dB _____ —
20.0-26.5 — >=11 dB ______ —
Uncertainty* >=ldB >=ldB >=2dB
4-8
UPDATES APPLY TO ALL SERIALS

HP 85027A/B/C Adjustments
5. Remove the printed, plastic switch configuration label from the back of the
bridge (additional labels are available as HP P/N 85027-80004).
6. Disconnect the power sensor from the attenuator. Turn on modulation. Con -
nect the bridge input port to the attenuator, leaving the test port open.
7. On the analyzer, turn on averaging (avg. factor =8), and the cursor. On the HP
8757A, turn on smoothing (5%).
8. Adjust R5 (see Figure 5-2) for a cursor reading of -6±0.1 dBm.
9. Set the attenuator to 30 dB. Adjust R29 (Figure 5-2) for a cursor reading of
calibrated -30 dB minus 6 ±0.1 dBm.
10. Set the attenuator to 0 dB and adjust R29 (if required) until the cursor reads -6
±0.1 dBm.
11. Repeat steps 8 through 10 until the change in level is equal to the calibrated 30
dB ±0.1 dB and, with 0 dB attenuation, the cursor indicates -6±0.1 dBm.
DC Adjustment Procedure
NOTE: You can perform this DC procedure only with an HP 8757A analyzer.
12. On the HP 8757A, set DC mode.
13. Set the reference level to -50 dBm at midscreen, and the scale to 5 dB/div.
14. On the source, turn off the RF power.
15. On the analyzer, press [CAL] [CONFIG SYSTEM]. If your analyzer has firm -
ware revision 2.0 or above, press [CAL] and select [MORE] [AUTOCAL],to turn
auto calibration OFF.
16. On the bridge, use a short jumper to short pad Y (where yellow wire termi -
nates) to ground.
17. Adjust R25 (Figure 5-2) for a minimum reading on the analyzer (it should be <-
50 dBm).
18. Remove the short, and turn auto cal back ON.
Feedthru Null Adjustment Procedure
19. On the analyzer, press [CAL] and select [DC DET ZERO] [AUTOZERO].
20. Adjust RiO (Figure 5-2) for as HIGH a trace as possible. Adjust slowly, because
averaging and smoothing mask adjustment effects. -
NOTE: Steps 19 and 20 must be repeated until no further change is noted.
5-3
UPDATES APPLY TO ALL SERIALS

HP 85027A/B/C Adjustments
DC Mode RF Adjustment Check
21. On the source, turn on the RF power.
22. Set the attenuator to 0 dB.
23. On the analyzer, verify DC mode, averaging, smoothing, and the cursor are still
on. Allow the trace to settle. Press [DISPLAY][MEAS-.MEM][MEAS-MEM].
The cursor should now indicate 0.0 dB.
24. Set the attenuator to 30 dB.
25. The cursor should now indicate the calibrated -30 dB to within 0.8 dB.
26. If the value indicated is not within 0.8 dB of the calibrated -30 dB, It may be
necessary to adjust R5 and R29 until the difference between the 0 dB and 30
dB attenuator settings is just within 0.8 dB of the calibrated 30 dB. Adjust R5
when the attenuator setting is 0 dB and R29 when at 30 dB.
27. If any adjustments are made, it will be necessary to repeat the AC Adjustment
Procedure again, only this time using a tolerance limit of ± 0.8 dB instead of the
0.1 dB indicated in steps 8 through 11. This will allow you to split the error
difference between the two modes of operation.
28. Both AC and DC dynamic accuracy specifications should be within the limits
stated in Table 1-1.
5-4
UPDATES APPLY TO ALL SERIALS

HP 85027A/B,/C
DIRECTIONAL BRIDGE
SERIAL NUMBERS
This manual applies directly to the HP 85027A/B/C
directional bridge with serial numbers prefixed as
follows:
Model
HP 85027A
HP 85027B
HP 85027C
Serial Prefix
2522A
2522A
2522A
For additional information about serial numbers, refer
to INSTRUMENTS COVERED BY MANUAL in
Section 1 and BACKDATING, Section 7.
© Copyright HEwLETr-PAcKARD COMPANY 1985
1400 FOUNTAINGROVE PARKWAY, SANTA ROSA, CA 95401 U.S.A.
MANUAL PART NUMBER 85027-90001
Microfiche Part Number 85027-90002
U. -
Box i~- ~ -
FF0 San FI~r~C~ ~ -
Printed: JULY 1985
4 HEWLETT
F PACKARD

HP 85027A/B/C Table of Contents
CONTENTS
Section Page
GENERAL INFORMATION 1-1
Introduction 1-1
Specifications 1-1
Safety Considerations 1-1
Instruments Covered by Manual 1-1
Description 1-3
Equipment Required But Not Supplied 1-3
Scalar NetworkAnalyzer 1-3
HP 8757A 1-3
HP 8756A 1-3
HP 8755C 1-4
Swept Signal Source 1-4
HP 8350B 1-4
HP 8340A 1-4
HP8341A 1-4
Detectors 1-4
Power Splitters 1-4
Equipment Available 1-4
Accessories Available 1-4
Recommended Test Equipment 1-5
Warranty Restrictions 1-5
2 INSTALLATION 2-1
Introduction 2-1
Initial Inspection 2-1
Preparation for Use 2-2
Power Requirements 2-2
Connecting the HP 85027 2-2
Mating Connectors 2-2
Operating Environment 2-3
Storage and Shipment 2-3
Environment 2-3
Packaging 2-3
3 OPERATION 3-1
Introduction 3-1
Operating Precautions 3-1
Connector Wear 3-1
Operating Instructions 3-1
Operator’sCheck 3-4
Equipment 3-4
Procedure 3-4
1

HP 85027A/B/C Table of Contents
4 PERFORMANCE TESTS 4-I
Introduction 4-1
Performance Test Record 4-1
Directivity 4-1
Description 4-I
Equipment 4-2
Procedure 4-2
Below 2 GHz 4..3
Above 2 0Hz 4-4
Test PortMatch 4-7
Specifications 4-7
Description 4-7
Equipment 4-8
Procedure 4-8
DynamicPower Accuracy (AC and DC) 4-9
Specifications 4-9
Description 4-9
Equipment 4-9
Procedure 4-10
5 ADJUSTMENTS 5-1
Introduction 5-1
Adjustment Procedures 5-1
AC Adjustment Procedure 5-2
DC Adjustment Procedure 5-3
Feedthru Null Adjustment Procedure 5-3
DC Mode RF Adjustment Check 5-4
6 REPLACEABLE PARTS 6-1
Introduction 6-1
Exchange Assemblies 6-1
Replaceable Parts List 6-1
Organization 6-1
Information 6-1
Ordering Information 6-2
7 MANUAL BACKDATING CHANGES 7-1
Introduction 7-1
Application 7-1
8 SERVICE 8-1
Introduction 8-1
Theory of Operation 8-I
Troubleshooting Procedures 8-2
GainingInternal Access 8-2
Cable ContinuityCheck 8-2
Power Cable Replacement 8-3
Input Port and Test Port Resistance Checks 8-3
Microcircuit Check 8-3
A2 Circuit Board Assembly Replacement 8-4
Al Bridge Microcircuit Assembly Replacement 8-4
Power Supply Check 8-5
Signal Path Check 8-7
Clock/Control Check 8-7
Connector Inspection 8-7
Visual Inspection 8-7
Mechanical Inspection 8-9
Gaging the Precision 3.5mm Connector 8-9
Gaging the APC-7 Connector 8-14
11