Fluke 9640A Series, Instruction Manual

Page: 236 / 324

9640A
Instruction Manual
5-46
Attenuation Accuracy – 75
Ω
(Optional)
Equipment required for this test:
•
Measuring Receiver
•
Precision Adapter, Type-N female-to-female, 75
Ω
•
Attenuator, 6 dB, Type-N (m) – (f), 50
Ω
•
75
Ω
to 50
Ω
impedance-matching pad
•
75
Ω
Leveling Head (supplied with UUT)
Note
In the following tests, the tolerances shown refer to specifications listed in
Chapter 1 of this manual. It may be necessary, in some cases, to alter the
test limits based on the uncertainty of the actual equipment used. For
example, if the Instrument specification is ±0.025 dB and the measuring
receiver uncertainty is ± (0.015 dB + 0.005 dB per 10 dB step) the test limit
for 18 dB would be ± 0.035 dB (the root-sum-square of 0.025 and 0.024).
Use the following procedure to verify the attenuation accuracy of the UUT output relative
to +16 dBm, 75
Ω
:
1. Connect the 75
Ω
Leveling Head to the RF INPUT of the measuring receiver via a
75
Ω
to 50
Ω
impedance-matching pad and 6 dB attenuator. Connect the REF
FREQUENCY OUTPUT (rear panel) from the UUT to the spectrum analyzer Ext
Ref In (on rear). See Figure 5-12 for equipment connections.
9610A/AF REFERENCE SOURCE
10V
PK
MAX
RF
COMMON
96xx
HEAD INTERFACE
RF OUTPUT
CONTROL
CONNECT
96xx HEAD
ONLY
STBY
NEXT
CHAR
6
9
5
8
4
7 7
3 2 1
-
-
0
.
SPACE EXP BKSP
ALPHA
LOCK LOCK
DEF
MNO
ABC
JKL
/ /
GHI
WXYZ TUV PQRS
ENTER
SINE
MOD
SWEEP
UNITS
SETUP
OPER
CAL
IEEE-488
SH1 AH1 T6 L4 SR1
RL1 PP0 DC1 DT0 C0 E2
MADE IN UK
FLUKE CORPORA TION
www.fluke.com
TO BE
APPLIED FOR
CONFORMS TO UL STD. UL61010A-1.
CERTIFIED TO CAN/CSA STD. C22.2 No.1010.1-92
SAFETY W ARNING
NOTE
DISCONNECT PO WER AND SIGNAL LEADS
BEFORE REMO VING CO VERS .
FOR CONTINUED PR OTECTION AGAINST ELECTRIC SHOCK
THE PO WER CORD PR OTECTIVE CONDUCT OR MUS T BE
CONNECTED TO SAFETY EAR TH ( GR OUND ).
FOR CONTINUED PR OTECTION AGAINST FIRE
USE 250V FUSE OF CORRECT RA TING.
READ OPERA TORS MANU AL BEFORE USE.
NO USER SER VICEABLE P ARTS CONT AINED, DO NOT
REMOVE CO VERS , HAZARDOUS VOLTAGES PRESENT .
REFER SER VICE TO QUALIFIED PERSONNEL.
115
230
T4.0 AH 250V
T2.0 AH 250V
LINE VOLTAGE
SELECTION
FUSE 5 x 20mm
IEC 127
POWER INPUT
230 VA MAX. FREQ 47 - 63 Hz
SERIAL POR T
FACTORY SET
REF FREQUENC Y
INPUT
REF F REQUENC Y
OUTPUT
6 7 8
ENABLE
DISABLE
1V PK INTO
TTL INTO
SWEEP TRIGGER
INPUT :
5V PK
AUX PROTECTIVE
EARTH (GROUND)
RF COMMON
RF COMMON
5V PK
MODULATION
LEVELLING AND
FREQUENCY PULL
INPUT
+
_
50
5V PK
+
_
50
+
OUTPUT : TTL NOM
INTO 1k
+
1k NOM
NOM 50
10V PK MAX
Front
Rear
75
Ω
Leveling Head
75

to 50

Impedance
Matching Pad
6 dB Attenuator
RF Input
Ext Ref Input
Spectrum Analyzer
Ref Frequency
Output
Instrument
ead225f.eps
Figure 5-12. Equipment Connections - Attenuation Accuracy Test (75
Ω
)