HP 8970b schematic
HP 8970B Option 020
Service Manual
Supplement
Service Manual Supplement
HP 8970B Option 020
HP Part no. 08970-90115
Edition 1
May 1998
UNIX is a registered trademark of AT&T in the USA and other countries.OSF/Motif is a
trademark of the Open Software Foundation, Inc. in the USA and other countries.
© Copyright Hewlett-Packard Company May 1998
All rights reserved. Reproduction, adaptation, or translation without prior written
permission is prohibited, except as allowed under the copyright laws.
Printed in the UK.
ii HP 8970B Option 020 Service Manual Supplement
Printing History
Printing History
Date
May 1998 1 08970-90115
Manual
Edition
Notes
HP 8970B Option 020 Service Manual Supplement iii
List of Related Publications
List of Related Publications
HP Part Number Title
08970-90054 HP 8970B Noise Figure Meter Service Manual
About this Manual
This document is a supplement to the HP 8970B Noise Figure Meter Service Manual
(08970-90054) and provides information useful for operating the HP 8970B Option 020. It
also gives some troubleshooting tips.
iv HP 8970B Option 020 Service Manual Supplement
Table of Contents
Page
Printing History.....................................................................................................iii
List of Related Publications .................................................................................. iv
About this Manual................................................................................................. iv
Block Diagram and Parts List.................................................................................... 1-1
Block Diagram......................................................................................................... 1-2
Front End ................................................................................................................1-3
Material List ........................................................................................................... 1-5
Theory of Operation..................................................................................................... 2-1
General.................................................................................................................... 2-2
Adjustments.................................................................................................................... 3-1
General.................................................................................................................... 3-2
Input power detector Gain and Offset Adjustment............................................... 3-2
600 MHz SAW Oscillator Frequency Adjustment................................................. 3-3
Board Differences .........................................................................................................4-1
General.................................................................................................................... 4-2
Microprocessor Board ............................................................................................. 4-2
20 MHz IF Assembly (08970-60050)......................................................................4-3
Driver Assembly (08970-60089)............................................................................. 4-4
Fault-Finding Tips........................................................................................................5-1
General.................................................................................................................... 5-2
Filter (0955-0634) ................................................................................................... 5-2
Input Assembly (08970-60097 or 08970-60125)....................................................5-3
YIG Tuned Oscillator (0955-0630)......................................................................... 5-4
Mixer (0955-0635)................................................................................................... 5-4
Isolator (0960-0638)................................................................................................ 5-5
4.5 GHz Low Pass Filter (9135-0169).................................................................... 5-5
Second Convertor (5086-7909) ............................................................................... 5-6
600 MHz SAW Oscillator (08970-60093)............................................................... 5-6
Board Details.................................................................................................................. 6-1
Contents-2 HP 8970B Option 020 Service Manual Supplement
1
Block Diagram and Parts List
Block Diagram and Parts List
Block Diagram
Block Diagram
Figure 1-1: HP 8970B Option 020 Front End Schematic
2.05 GHz Low Pass Filter
W1
PAD 1
PAD 2
PAD 3
W6
4.5 GHz LPF
O/P
J1
(924)
(925)
(926)
ISOLATOR
J2
+15 V (2)
20 dB AMP (923)
DETECTOR (927)
INPUT ASSEMBLY
I/P
-15 V (7)
W5
W8
J4
RF
J3
J5
J2
50 Ω
MIXER
W2
IF
TO A4 ASSEMBLY
4 - 6 GHz
Y.T.O
W3
W4
LO
J1
W7
92
0
92
2
J4 J3
J5
Second Convertor
1-2 HP 8970B Option 020 Service Manual Supplement
LO MONITOR
W9
600 MHz SAW
Oscillator
Front End
Block Diagram and Parts List
Front End
Figure 1-2: HP 8970B Front End Schematic
2050 MHz LPF
J1
10 - 2047 MHz
Limiter
10 dB
20 dB
INPUT ASSEMBLY
Limiter (on 08970-60125
Input Assembly only).
Suppresses externally
generated transients.
10 dB
2-7 GHz Isolator
10 dB
Detector
Diode
Output
4.5 GHz LPF
2 dB
J3
YTO Output
3.910 - 5.947 GHz
J2
J5
J4
600 MHz
3.9 GHz
300 MHz
To A4 Assy
3.6 GHz
X 6
2nd Convertor
HP 8970B Option 020 Service Manual Supplement 1-3
Block Diagram and Parts List
Front End
Figure 1-3: Schematic Representation of Input Assembly
PAD 1 20 dB
Limiter
10 dB
PAD
Limiter (on 08970-60125
Input Assembly only).
This is a schematic representation of the RF input assembly. The amplifier section and
each and each of the attenuator sections are switchable by the control lines.
On units using the Input Assembly 08970-60125, the Limiter suppresses externally
generated transients.
In Figure 1-1 the numbers in brackets inside the input assembly refer to the wire colors.
The numbers at the side of the second convertor refer to the wire colors attached to the
connector which connects up to the second convertor.
20 dB
AMP
Amp
PAD 2 PAD 3
10 dB
PAD
10 dB
PAD
Detector
3 GHz
LPF
2dB
PAD
1-4 HP 8970B Option 020 Service Manual Supplement
Loading...