3. INSTALLATION
3.1 Geneml lnstellstion Conridemtioos
The ORTEC 444 is designed for installation in 8 stendard Bin and Power Supply, such es the ORTEC
401A/402A. Since this bin isintended for reck mounting, it is IWCBSIB(~to ensure that envvecuum tube
equipment operated in the seme rack will have adequate cooling air circulation to prevent any localized
heating of the 444 transistorized circuits. The temperature of equipment mounted in recks ten easily
exceed the recommended maximum unless precautions are observed. The ORTEC 444 should not be
subjected to temperatures in excessof 1200F KQOC).
3.2 connection to Power
The ORTEC 444 contains no internal power supply; therefore, it obteins its dc operating power from
the standard Bin and Power Supply in which it isinstalled. Always turn power off for die Bin and Power
Supply before inserting or removing any modules. The ORTEC 400 Series of moduler instruments we
designed such that it is not possible to overload the power supply with e full complement of modules in
the bin. However, this may not be true when the bin contains modules other than those of ORTEC
design; check the power supply for any werloed conditions bv testing the dc power levelsafter insertion
of ali modules.
The ORTEC 444 may be operated outside the 4OlA/402A Bin and Power Supply. using e power ex-
tension cable. Be sure that the cable used accents properly for the grounding circuits recommended in
AEC standards of TID-20893 (Rev.). Ground connections ere included to ensure proper reference
voltage feedback into the power rupplv, and these mun be preserve&by the remote cable. Be careful
to avoid ground loops when the module is not phvsicellv installed in the bin during operation.
3.3
3.4
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Lineer Input Connection .
Lineer input pulses ten be furnished from any ORTEC linear module of the 400 Series. These include
amplifiers, delay circuits, gates, and other pulse handling equipment. The effective input range will be
from the adjusted discriminator level (to.1 to 1Vi up through +lO volts.
When the linear input signalsere furnished through e cable more than four feet long (approximately).
the input should be terminated with the characteristic impedance of the cable. This ten usually be
avoided when shorter cables ere used.
Linear Output Connections
The shaped linear output pulses can be furnished into any other ORTEC Series 409 linear module. or
directly into the ADC input of a multichannel analyzer. It is impoftent to preswye the pulse shape and
amplitude of the output, thus the interoonwcting cable should always be properly terminated. Either of
two standard output impedances may be selected, according to the type cad length of interconnecting
cable and the input impedance of the instrument to which it is connected. The output is available
through e front panel connector, with an output impedsnce of lessthan 1 ohm. or through II rear panel
cowwctor, with 2, - 93 ohms. For most applicetiom proper resistive termination of the cable is
attained by either of two methods indicated below.
One method is the seriesn/pa tormination.“sing the reer panel 93fi Output connector and an appro.
priate length of 93 ohm coaxial cable to transfer the signal into the next module or inrtrument. The
input impedance of the next equipment will probably be on the order of 1ODOohms or more. The total
amplitude of each output pulse will be divided between the 93 ohm output impedance of the 444 and
the input impedsnce of the next module, so e high input impedance is desirable when this se&a
termination method is used.
An alternate method depends upon hunt termination et the remote end of the cable. For this, “se the
front penel 1R Output connector, and whatever type cosxial cable is desired. Then use a ENC Tee et
the input to the next module, to eccept both the cable and e BNC Terminator, selected to match the
characteristic impedance of the cable when connected in parallel with the instrument’s input impedance.
For convenience, ORTEC otockra limited quantity of BNC Tee.conrwctors. in both SOand 100 ohm BNC
. Terminators.
