TM 11-6625-1683-15
and series resistors R53, R72, R73, and R74,
5-26. Block 2900 Range Amplifier Test
which terminate at ground. The brightness
Circuit
controlling voltage set by R49 is brought to
pin J 16-7. The junction point of R49 and
Connector J25 provides a means of circuit
R 5 0 connects to pin J16-9. The focusing
and power connection to the radar set range
voltage set by R51 is brought to pin J16-11.
amplifier assembly. ON/OFF switch S25 is a
c. The B-scope voltage divider consists of
three-pole, two-position toggle switch. One
internally mounted B-bright potentiometer
pole applies 12 volts to pin J2511. The
R 4 6 , which establishes image brightness;
second pole furnishes + 12 volts to pin J25-4.
series resistor R47; internally mounted B-
The third pole feeds +35 volts to pin J25-6.
focus potentiometer R48, which controls im-
In the OFF position, these poles are, respec-
age spot size; and series resistors R52, R69,
tively, connected to dummy load resistors R58,
R70, and R71, which terminate at ground.
R59, and R57. TEST jack TP55 permits moni-
The brightness controlling voltage set by R46
toring the range-delayed trigger output and
is brought to pin J16-12. The junction point
connects to pin J258.
of R46 and R47 connects to pin J16-10. The
focusing voltage set by R48 is brought to pin
5-27. CRT TEST Circuit
J1614, and + 110 volts is applied to pin
J16-1.
a. Connector J16 provides a means of con-
d. In the deflection control circuit, + 300
necting gun voltages to the Ascope and B
volts is impressed across series resistors R60
scope. Deflection voltages for these tubes are
and R62. The + 150-volt junction of R60 and
applied through connector J17. Gun voltages
R 6 2 is joined to pins J17-A and J17-D.
are derived from the block 2300 power con-
The low side of R62 is brought to pin J17-H,
verter. The 2,000-volt dc output is controlled
which is also grounded. DEFL potentiometer
by two-pole press-and-hold switch S17. One
R61 bridges R60 and R61 and enables the
pole carries the + 2,000 volts to pin J16-13.
operator to vary the spot position on the scope
The other pole applies 2,000 volts dc to a
being tested. The variable voltage output of
parallel voltage divider network.
this potentiometer is connected to pins J17E
and J17F.
b. One branch of the voltage divider net-
w o r k supplies the Ascope and the other
5-28. AUDIO Output Circuit
branch supplies the B-scope. The A-scope
voltage divider consists of internally mounted
A - b r i g h t potentiometer R49, which estab-
AUDIO jack J26 is connected between pin
lishes the image brightness; series resistor
J6-2 and ground. It permits the audio output
R50; internally mounted A-focus potentio-
signal from block 400 audio amplifier to be
aurally monitored.
meter R51, which controls image spot size;
5-14
AGO 7918A