EG&G ORTEC 463 Bedienings- en onderhoudshandleiding - Pagina 8
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Type BNC connector on front panel accepts input signals
from preamplifier or from shaping amplifier; dc-coupied
and baseline restored; normal range from Disc Level to
-10 V; Z|n 50n.
OUTPUTS
NEC Two NIM-standard Fast Negative logic output signals
generated separately and furnished through two type BNC
connectors on front panel; nominal -16 mA (800 mV on
50fl load), width <10 nsec, f;-<2.5 nsec.
PCS
NIM-standard Slow Positive logic output signal
furnished through type BNC connector on front panel;
nominal -i-5 V, width 500 nsec, tf <25 nsec; Zq <10J2.
ELECTRICAL AND MECHANICAL
POWER REQUIREMENTS
+24 V, 25 mA; +12 V, 28 mA;
-24 V,90 mA; -12 V, 170 mA.
WEIGHT (SHIPPING) 4.5 lb (2 kg).
WEIGHT (NET) 2.5 lb (1.1 kg).
DIMENSIONS
NIM-standard single-width module (1.35
by 8.714 in.) per TID-20893 (Rev.).
3. INSTALLATION
3.1. GENERAL
The 463 is used in conjunction with an ORTEC 401/402
Bin and Power Supply, which is intended for rack mount
ing. Therefore if vacuum tube equipment is operated in the
same rack, there must be sufficient cooling with circulating
air to prevent any localized heating of the all-transistorized
circuitry used throughout the 463. The temperature of
equipment mounted in racks can easily exceed the recom
mended maximum l imit of 120°F (50°C) unless these
precautions are taken.
3.2. CONNECTION TO POWER
Always turn off power for the Power Supply before
inserting or removing modules. The ORTEC 400 Series
of modular instruments is designed so that the Power
Supply cannot be overloaded when there is a ful l comple
ment of modules in the Bin. Since, however, this may
not be true when the Bin contains modules other than
those of ORTEC design, use the convenient test points
on the front panel of the 401/402 to check each Power
Supply voltage level after all modules have been inserted.
3.3. INPUT CONNECTION
The Input circuit of the 463 is designed for use with 50T2
cable. The input impedance is 50T2; so no external
terminator is required for this connection.
The input can come from a detector or photomultiplier
directly, provided that the negative input pulse wi l l have
sufficient amplitude to exceed a Disc Level setting in the
463. When an amplitude requires amplification or when
additional pulse shaping is required [such as with Ge(Li)
coaxial detectors], an ORTEC 454 Timing Filter Amplifier
can be used between the detector and the input to the 463.
3.4. OUTPUT CONNECTIONS
There are three outputs on the 463, and all connectors
are located on the front panel. Two of these are NIM-
standard Fast Negative pulses that are generated sepa
rately and are therefore completely isolated. The third is
a NIM-standard Slow Positive pulse. Al l three pulses are
furnished for each input pulse that exceeds the Disc
Level setting.
The Fast Negative output pulses are intended for timing
applications such as the Start and Stop inputs to a time
to pulse height converter. Either or both may be used and
the alternate connector does not need to be terminated
when it is not being used. Since the NIM-standard Fast
Negative pulse is a current pulse and since it is intended
for use with a 50r2 load, you should use 50T2 cable to
connect it to the point where it will be used and that point
must be terminated in 50n. Normally the instrument that
receives the pulse will have a 50J2 input impedance; if
it does not, use an external termination at the receiving
end of the cable.
The NIM-standard Slow Positive output pulses can be
used for coincidence work or can be counted directly
in a sealer or ratemeter. It is normal to use 93Q cable to
transfer this voltage pulse that is furnished through the
output impedance of <10J2. For cable lengths longer than
2 meters {^7 ft) it is recommended that the cable be
terminated in its characteristic impedance. This output
can also drive a terminated 50n cable, but with a slightly
reduced amplitude.