3
WEIGHT
Net 1.5 kg (3.3 lb).
Shipping 3.1 kg (7.0 lb).
DIMENSIONS NIM-standard single-width module
3.43 × 22.13 cm (1.35 × 8.714 in.) per DOE/ER-
0457T.
3. INSTALLATION
The Model 863 contains no internal power supply
and must be powered from a NIM-standard bin and
power supply. The bin and power supply should be
turned off when modules are inserted or removed.
The power supply voltages should be checked after
modules are inserted. Ensure that the Model 863
has sufficient cooling air circulating to prevent any
localized heating of the circuitry. The Model 863
should not be subjected to temperatures greater
than 50
E
C.
4. CIRCUIT DESCRIPTION
The Model 863 is composed of four separate timing
filter amplifiers constructed on the same PWB. Each
section is identical, and the circuit description that
follows relates to any of the four sections.
Component designations are the same for each
channel.
Each section of the 863 consists of a hybrid
differential amplifier, A1. The nominal gain of the
input section is 1×. The overall amplifier polarity is
selected by jumper W1 located on the PWB. See
Fig 4.1 for an illustration of jumper selection settings
on the PWB. To access this and other jumpers,
remove the left side cover of the module. The 863 is
shipped with the polarity set as noninverting.
W1
Jumper selection for invert/noninvert
W2 and W3
Jumper selection for setting differ-
entiation (both jumpers should be set
identically)
W4
Jumper selection for setting inte-
gration
W5
Jumper selection for setting coarse
gain
The differentiation circuit follows the input stage and
consists of a CR filter and a pole-zero cancellation
network. Both jumpers W2 and W3 should be set
when selecting the differentiation time constant.
Three differentiation time constant positions are
available: Out, 200 ns, and Optional. The 863 is
shipped with the W2 and W3 jumpers in the Out
position. The Optional selection requires the addition
of resistor R5 and capacitor C7. The following table
lists values of R5 and C7 corresponding to different
differentiation time constants.
Differentiation
Time Constant
R5
C7
20 ns
499k
47 pF
50 ns
215k
150 pF
100 ns
100k
270 pF
200 ns
51k
470 pF
500 ns
21k
1200 pF
The Fine Gain stage is built around hybrid amplifier
A2 and is adjusted by the front-panel potentiometer,
R11. The overall gain of this stage ranges nominally
from 0.2× to 5×, and is inverting.
The integration circuit follows the Fine Gain stage
and consists of an RC network. Jumper W4 selects
the integration time constant as Out, 50 ns, or
Optional. The 863 is shipped with the W4 jumper in
the Out position. The Optional selection requires the
addition of capacitor C12. The following table lists
values of C12 corresponding to different integration
time constants.
Following the integration circuit is the Coarse Gain
stage built around hybrid amplifier A4. The Coarse
Gain can be selected as either nominally 1× or 5×
Summary of Contents for 863
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