Assembly Instructions Chapter 4

4-6 kW UHF Translator Chapter 4, Circuit Descriptions
837B, Rev. 0 4-2
Red LED (DS9) and a VSWR Cutback,
Amber LED (DS7).
4.0.2 RF, Baseband Input and
Remote Connections
The RF, Baseband Video and Audio
Inputs to the Translator, connect to the
(A9) Remote Interface Panel located on
the rear of the Single UHF Exciter
Assembly. The On Channel RF input
connects to the “F” connector J3 for
75 or the “N” connector J1 for 50.
If the (Optional) Modulator Kit is
present, the Baseband Video Input
connects to Jack J2 that is wired to J1
on the Exciter. The Baseband Audio
Input connects to the Terminal Block
TB1 for Balanced Audio or to Jack J6
that is wired to J3 on the Exciter, for
Composite, Stereo, Audio.
Remote Monitoring and Operation of
the Translator is provided through the
Jacks (J8, J9 & J10) located on (A9) the
Remote Interface Assembly mounted
toward the rear of the Single UHF
Exciter Assembly. Jack (J7) should
have a dummy plug connected to it,
which has a jumper connected between
Pins 1 & 2, that provides the Interlock
to the Exciter needed to operate the
Translator. If the Jumper is missing,
the Translator will not switch to
Operate. If remote connections are
made to the Translator they should be
made through the plugs provided in the
Installation Material as noted on the
Interconnect Drawing (1278-8400) for
the Single UHF Exciter.
4.0.3 AC Input
The Single UHF Exciter Assembly needs
an AC input of 208/240 VAC at 20
Amps. The AC Input to the Single UHF
Exciter Assembly connects to (A8) the
AC Distribution Assembly, UHF Exciter
Assembly (1245-1500) located in the
right, center rear of the Cabinet. The
Assembly contains the 4 Terminal Block
(TB1) to which the 208/240 VAC
connects. Line 1 to TB1-1A, Line 2 to
TB1-3A and Safety Ground to TB1-2A.
The AC Distribution Panel contains CB1
one 20 Amp Circuit Breaker that
supplies the AC to the rest of the Single
Exciter Assembly.
The Input AC is connected to (CB1) the
Main AC Circuit Breaker (20 Amps).
The output of CB1 has three MOVs,
VR1 connected from Line 1 to ground,
VR3 connected from Line 2 to ground
and VR3 connected across the two legs.
The AC output of CB1 connects to A1
and A2 that are IEC Outlet Strips. The
(A1) Exciter Tray and the (A4) Variable
Gain/Phase Tray plug into the (A1) IEC
Outlet Strip. The (A5) Variable
Gain/Phase Tray, the (A8) Metering
Panel and the (A7) Receiver Tray plug
into the (A2) IEC Outlet Strip.
When the Circuit Breaker CB1,
mounted on the AC Distribution
Assembly, is switched On, +12 VDC
from the Exciter, is supplied to the two
Amplifier Arrays for the operation of the
LED Status Indicators in each of the
UHF Amplifier Trays. The +12 VDC is
also connected to the (Optional)
External Exhaust Kits in each of the
Amplifier Arrays, if purchased.
4.1 (A7) UHF/VHF Receiver
(1142479 or 1265-1100; Appendix
C)
The UHF/VHF Receiver Tray
w/(Optional) Frequency Correction
selects the desired UHF or VHF On
Channel Input Signal and converts it to
a Combined IF Signal of 45.75 MHz
Visual + 41.25 MHz Aural. The Tray
also has provisions for a Frequency
Correction Option that consists of a
VCXO Channel Oscillator Assembly with
a PLL Circuit which maintains an exact
IF Output Frequency, over the capture
range of the PLL circuit, even if the
Input UHF or VHF frequency varies.