Assembly Instructions Chapter 4

4-6 kW UHF Translator Chapter 4, Circuit Descriptions
837B, Rev. 0 4-33
adjust Pot (A7) connects through the
Metering Board to J4 on the Variable
Phase/Gain Board which controls the
phasing of the RF output. The Phasing
adjust is needed to phase the two RF
outputs of the Amplifier Arrays, when
they are combined, to achieve
maximum output. The phase and level
controlled RF signal connects to J2 of
the Variable Phase/Gain Board which
connects to the RF Output Jack J3
located on the rear panel of the Tray.
A sample of the RF from the Variable
Phase/Gain Board connects to J4 the
output Sample Jack located on the
front panel of the Tray.
4.3.2 (A5) Metering Board (1245-
1202; Appendix D)
A detected output sample level
connects to the Metering Board at J7
Pins 3 & 4 which is connected to the %
Power Level position on (A6) the front
panel meter of the Tray. S1 is a two
position front panel mounted switch
that allows the operator to view the
ALC Level, typically reads .6V - 1V, or
the % Power, which is calibrated for
100 % is +23 dBm output.
4.3.3 (A1) Power Entry Module
Assembly (1227-1206; Appendix
D)
120/240 VAC connects to the Tray at J2
on (A1) the Power Entry Module
Assembly. Jumpers on the Power Entry
Module are set for the desired AC
Voltage Input. The assembly contains
an On/Off Switch, two 4 Amp Fuses
and three Varistors for AC line
protection. The AC is connected to
(A2) a step down Toroid that supplies
an 18 VAC output to the +15VDC/-
12VDC Power Supply Board.
4.3.4 (A3) +15V/-12V Power
Supply Board (1245-1203;
Appendix D)
The +15 VDC and -12 VDC needed to
operate the boards in the Tray are
generated on (A3) the +15 VDC/-12
VDC Power Supply Board (1245-1203).
The +15VDC/-12VDC Power Supply
Board supplies voltage regulated +15
VDC and -12 VDC Outputs to the rest
of the Tray. The Green LED DS1 is lit if
+15 VDC is present and the Green LED
DS2 is lit if -12 VDC is present at the
output of the +15V/-12V Power Supply
Board.
4.4 (A6) Metering Panel (1136811
or 1245-1400; Appendix C)
The Metering Panel provides three
meters, one for Combined, one for Side
A Amplifier Array and one for Side B
Amplifier Array Outputs. The Side A
Meter (A15) displays the % Forward
and the % Reflected Power samples for
the Side A Amplifier Array. The Side B
Meter (A17) displays the % Forward
and the % Reflected Power samples for
the Side B Amplifier Array. The
Combined Meter (A13) displays the %
Reject, % Visual, % Aural and the %
Reflected Power samples for the
Combined Output of the 4-6 kW
Translator. The Metering Panel also
takes the ALC Reference Inputs from
the (A4 & A5) Variable Phase/Gain
Trays and splits them six ways which
are then connected to the UHF
Amplifier Trays in the two amplifier
arrays.
The Metering Panel (A6) contains (A4,
A5, A6 & A11) four Splitter Boards
(1181-1002), (A7, A8 & A9) three Dual
Peak Detector Modules (1159965),
(A10) a Visual/Aural Metering Board
(1265-1309), (A18) a Detector
Threshold Board (1245-1402) and (A3)
a ±12V Power Supply Board (1062-
1013).
The (A13) Front Panel Meter monitors
the Combined Output Power and is
controlled by (S1) the Meter Control
Switch. The (A15) Front Panel Meter
monitors the Side A Output Power with
(S2) the Meter Control Switch. The
(A17) Front Panel Meter monitors Side