Model 3585A
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To check which filter stage is causing the problem, use Test Mode 09 and the
jumpers on the board for each crystal stage. For example, to check the first
crystal stage:
•
Input the rear panel lOMHz to the 50n input.
•
Place Al 1 15 in the test position.
•
Enter:
RECALL 609
INSTRUMENT PRESET
CF STEP SIZE
FREQUENCY SPAN
RES. BW
1 . 1 Hz (selects the Al l board)
50kHz*
300Hz*
•
Check the 60dB points using the Offset function. The 60 dB points should
be approximately
::s;
(Res . BW* x 1 1 ). (The actual limit depends on the
3dB Bandwidth)
Each crystal stage may be checked in this manner by selecting the correct CF
Step Size (1 .2Hz for the A12 board, 1 . 3Hz for the A 1 3 board) and the ap
propriate jumper.
When you find the crystal stage whose Shape Factor is too large, go to Table
8-A-3-8 and select the next smaller resistor from the padding list. One resistor
is used per stage per bandwidth to determine the bandwidth (see Figure
8-A-3-5) .
3 0 0 H z
t
C E N T E R
F R E O .
T
3 H z
C E N T E R
\
R E O .
OP
O U T
3 0 0 H z
sw
1 0 0 H z
3 0 H z
s w
sw
C R Y S T �L S E R I E S
RE S I S T I\ N C E
C "
"-
3 H Z
'
sw
3 H z
S Y M M E T R Y
- 1 5 V
'====
S I\ N DW I D T H
====i
S E L E C T I ON RE S I S T O R S
Figure B·A·3·5. Crystal Stage
3SIS-I-fl-3-Z7
·Other Res. BW's and Frequency Spans may be used if the Shape Factor
of
another Crystal BW (3Hz - 300Hz) is
in error.
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Summary of Contents for 3585A
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