Westinghouse Type KR, Инструкция по установке и эксплуатации

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TYP E K R CARRI E R SET
quencies below 1 10 kc, these C!J.pacitors are 270
mmf. each. For frequencies of 1 10 kc and above, the
capacitors are 140 mmf. each.
C A U T 10 N
Turn power OFF before removing filters
or transistors, as high fransient currents may cause
p ermanent damage to the transistors.
M A I N T E N A N C E
Voltage values should be recorded after adjust­
ment in order to establish reference values which will
be useful when checking the apparatus. The readings
will remain fairly constant over
an
indefinite period
unless a failure occurs. However,
if
transistors are
changed, there may be considerable differ ence
in
these readings without the overall performance being
affected.
Typical voltage and current values are given as
follows. Voltages should be m easured with VTVM.
Readings m ay vary as much as ±20%.
In the following paragraphs, the transmitter m ay
be unblocked (transmitting) by closing the CARRIER
START circuit in the case
of
H ZM relaying, and by
opening the CARRIER START circuit in the case of
K-DAR and GCY relaying.
1. For D-C pin j ack m easurements with reference
to B-, refer to Table 1 .
2 . For transistor D-C measurements with reference
to B-, refer to Table 2.
3. For D-C bleeder measurem ents with reference
to B-, refer to Table 3.
4. For typical RF signal m easurements for re­
ceiv-er, refer to Table 4.
5. For typical RF signal m easurements for
transmitter, refer to Table
5.
6. Removal of Printed Circuit Board from
Flexite st Case.
To remove the printed circuit board, unplug J- 15
and J- 16 located near the output filter. Loosen the
two screws inside the case near the top. Loosen the
slotted thumb screws at the lower end of the board
and pull these screws out as far as they will extend.
Also remove the receiver coaxial cable plug.
Pull board down so as to disengag e the terminals,
and lift out.
7. Removal of the Output Filter
After the printed board has been removed, re­
move the screws on the outside of the case at the
bottom. Lift out filter and disconnect the coaxial
cable.
8. Receiver Filters
Fig. 1 2 shows typical receiver selectivity curves
both RF and IF. If the filters are checked in a test
setup, it is necessary to use an accurate signal gen­
erator or preferably a signal generator and a frequency
counter. Hewlett-Packard Type 400C or equivalent
should be used.
9.
Minimum Test Equipment for Installation
a. Milliammeter 0-25 rna DC.
b.
60-ohm 5-watt
non-inductive resistor.
c. A-C Vacuum Tube Voltmeter (VTVM). Voltage
range 0.003 to 30 volts, frequency range 60 cycles/
sec to 230-kc, input impedance 7. 5
megohms.
d. D-C Vacuum Tube Voltmeter ( VTVM)
Volta�e Range: 0 . 15 to 300 volts
Input Impedance: 7. 5 megohms
10. Desirable Test Equipm ent for Apparatus
Maintenance
a. All item s listed in Sect ions 8 and 9.
b. Signal Gener a t o r
Output Voltage: up to 8 volts
Frequency Range: 20-kc to 230-kc
c. Oscilloscop e
d. Ohmmeter
e. Capacitor checker
f. Test harness (S ee Fig .
19)
9
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