UBS Axcera 837B-5 Users Manual
4-6 kW UHF Translator Chapter 2, System Description
Chapter 2
System Description
The 837B is a complete 4-6 kW UHF Solid
State Internally Diplexed Television
Translator which operates at a nominal
Visual Output Power of 4000 - 6000
Watts Peak of Sync and Average Aural
Output Power of 400 - 600 Watts, at an
A/V Ratio of 10 dB, 10 % Sound or 200 300 Watts at 13 dB, 5 % Sound. The
837B is made up of three Cabinets, a
UHF Single Exciter Cabinet and two
Amplifier Array Cabinets.
2.1 System Overview
The standard 837B is functionally
comprised of (A1) a Single UHF Exciter
Table 2-1. UHF Exciter Assembly Trays and Assemblies
MAJOR ASSEMBLY
DESIGNATOR
A1 UHF Exciter, M/N 1142458
A3 2-way splitter assembly ZSFC-2-2SMA
A4 Phase/Gain Tray 1245-1200
A5 Phase/Gain Tray 1245-1200
A6 Metering Panel 1136811
A7 UHF receiver tray 1265-1100
A8 AC Distribution Assembly 1245-1500
A9 Remote Interface Assembly 1245-1801
The UHF Exciter Tray operates using
either the IF Output from the (A7) UHF
Receiver Tray connected to J1 on the ALC
Board (1265-1305) or the Combined IF
Output generated from the (Optional)
Baseband Audio and Video Inputs
connected to J32 on the ALC Board. The
two IF Outputs are connected to the IF
Relays K3 and K4, located on the ALC
Board and by applying or removing a
Jumper on Jack J8 Pins 10 & 11 located
on (A9) the Remote Interface Assembly
(1245-1801) the IF Output is selected.
To select the output from the Modulator,
J8-10 and 11, must be connected
together. To select the output from the
Receiver Tray, J8-10 and 11, must not be
connected together.
TRAY/ASSEMBLY NAME PART NUMBER
Assembly, (A2 & A3) two 2-3 kW
Amplifier Array Assemblies, (A4) a Hybrid
Combiner Assembly and (A11) an Output
Coupler Assembly. A sample is taken
from the Hybrid Combiner and connected
to (A7) a Directional Coupler.
2.1.1 (A1) UHF Exciter Assembly
(1278-1400; Appendix C)
The (A1) UHF Exciter Assembly is made
up of the trays and assemblies listed in
Table 2-1.
The UHF Receiver Tray (1265-1100)
takes the received RF On Channel
Frequency and generates a 45.75 MHz +
41.25 MHz Combined IF Output. The
Combined IF Output of the Receiver Tray
connects to J6 on the rear of the (A1)
UHF Exciter that is wired to J1 on the ALC
Board. With Receiver selected, no
connection between J8-10 and 11 on the
Remote Interface Assembly, the IF
Output from the Receiver Tray connects
through the Relays to the rest of the ALC
Board.
The (Optional) Baseband Audio, from
TB1 or J3, and Video, from J1, connect
to the UHF Exciter which produces a
Combined IF Output that connects to
J32 on the ALC Board.
837B, Rev. 0 2-1
4-6 kW UHF Translator Chapter 2, System Description
To select the output from the Modulator,
J8-10 and J8-11, must be connected
together.
The Exciter RF Output of the (A1) UHF
Exciter at J15 (+10 to +20 dBm) is
connected to the S Input on (A3) the
Splitter. The Exciter Output is split two
ways by A3 with RF Output #1
connected to the input of the (A5)
Variable Phase/Gain Tray (1245-1200)
and RF Output #2 connected to the
input of the (A4) Variable Phase/Gain
Tray (1245-1200).
The Variable Phase/Gain Tray sets the
phase and gain adjustments of the RF to
provide maximum output when the
outputs of the two Amplifier Arrays are
combined. The output of the (A4)
Variable Phase/Gain Tray (+16 dBm)
connects to (A2) the Side A 2-3 kW
Amplifier Array Assembly. The output of
the (A5) Variable Phase/Gain Tray
(+16 dBm) connects to (A3) the Side B
2-3 kW Amplifier Array Assembly.
The 208/240 VAC Input to the 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 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 Assembly contains
(CB1) the Main Circuit Breaker (20
Amps) that supplies the AC to the rest of
the Single Exciter Assembly. The output
of CB1 has three MOVs, VR1, VR2 and
VR3, connected to it, VR1 from Line 1 to
ground, VR3 from Line 2 to ground and
VR2 connected across the two lines. The
AC output of CB1 is wired to A1 and A2
that are IEC Outlet Strips. The (A1)
Exciter and the (A4) Variable Phase/Gain
Tray plug into the (A1) IEC Outlet Strip.
The (A5) Variable Phase/Gain Tray, the
(A6) Metering Panel and the (A7)
Receiver Tray plug into the (A2) IEC
Outlet Strip.
When the Circuit Breaker CB1 on the
Single UHF Exciter Assembly is switched
On, +12 VDC from the Exciter is
connected to A9-TB1 in each of the
Amplifier Array Cabinets. The +12 VDC
is split 4-6 Ways on the terminal block
A9-TB1 and connected to each of the
UHF Amplifier Trays at J3-7. The +12
VDC is used for operation of the LED
Status Indicators in the UHF Amplifier
Tray. The +12 VDC is also connected to
J4-20 and then to A9-TB2 for the
(Optional) External Exhaust Kit in each
Amplifier Array. When the UHF Exciter
Tray, Translator, is switched to Operate,
an Enable is applied to each of the 2-3
kW Amplifier Arrays at J4-15 that
connects to A9-TB2. The Enable is split
4-6 Ways on the terminal block A9-TB2
and connected to each of the UHF
Amplifier Trays at J3-9. This Enable
turns on the +32 VDC Power Supply in
each Amplifier Tray. Also a Fan Enable is
connected to J4-19 and then to A9-TB2
that connects to the (Optional) External
Exhaust fan mounted on the roof of each
Amplifier Array Cabinet, turning it On.
2.1.2 (A2 & A3) 2-3 kW Amplifier
Arrays (1278-1300; Appendix C)
The (A2 & A3) 2-3-kW Amplifier Arrays
are identical and are made up of the
trays and assemblies listed in Table 2-2.
837B, Rev. 0 2-2
4-6 kW UHF Translator Chapter 2, System Description
Table 2-2. Amplifier Array Trays and Assemblies
MAJOR ASSEMBLY
DESIGNATOR
A1, A2, A3, A4, A5(5kW) &
A6(6kW)
TRAY/ASSEMBLY NAME PART NUMBER
(Low Band) 1301560,
UHF Amplifier Trays, LDMOS
(Mid Band) 1301561,
Or (High Band) 1301562
A7 4, 5 or 6 Way Combiner Various
A8 Output Coupler Assembly 1016-1043
A12 Reject Load Assembly 1278-1312
A9-A1 8-Way Splitter 1245-1701 (ZFSC-8-43)
A10 AC Distribution Assembly
Three Phase 1278-1100
Or Single Phase 1278-1200
A11 Interface Assembly 1131532
The (A2 & A3) Amplifier Array Assemblies
each contain (A9-A1) an 8 Way Splitter
(ZFSC-8-43), four, five or six {A1, A2,
A3, A4, A5(5kW) & A6(6kW)} UHF
Amplifier Trays, LDMOS, (A7) a 4, 5 or 6
Way Combiner, (A12) a Reject Load
Assembly, (A8) an Output Coupler and
(A10) an AC Distribution Assembly, Three
Phase (1278-1100) or Single Phase
(1276-1200). The reject output from the
Combiner connects to (A12) a Reject
Load Assembly, which contains (A12-A2)
a Combiner Reject Load Board (1278-
1311) in a 5 or 6 kW configuration.
The RF Input (+16 dBm) from the
Variable Phase/Gain Tray connects to J1
on (A11) the Interface Panel located in
the Amplifier Array Assembly. The RF is
connected to the COM Input of (A9-A1)
the 8 Way Splitter that splits it eight
ways. The outputs (+6 dBm) connected
to J1, the RF Input Jack on each of the
UHF Amplifier Trays or are terminated
with 50Ω. Each of the UHF Amplifier
Trays amplify the RF signals to the power
needed to produce the total output power
for the Translator, with a maximum of
600 Watts per Tray. The outputs (+57.5
to +60 dBm) of the UHF Amplifier Trays,
LDMOS are combined in the (A7) 4, 5 or
6 Way Combiner assembly. The output
of the combiner is cabled to (A8) the
Output Coupler Assembly that supplies a
Forward and a Reflected Power Sample of
the output from the Amplifier Assembly
to the Metering Panel in the Single
Exciter Assembly. The reject output of
the Combiner, in a 5kW or 6kW
configuration, connects to (A12) the
Reject Load Assembly that dissipates any
reject due to miss-tuning or a
malfunction in any of the Amplifier Trays.
The RF Output of the Coupler at J2
(+63.5 to +65.2 dBm) is the RF output
of the 2-3 kW Amplifier Array.
In each UHF Amplifier Tray, a Forward
Power Sample and a Reflected Power
Sample, from the Combiner Board, are
connected to the Dual Peak Detector
Board, Single Supply. The Dual Peak
Detector provides peak detected forward
samples to the Amplifier Control Board
that supplies the samples to the front
panel meter of the UHF Amplifier Tray.
Before exiting each UHF Amplifier Tray
the RF is fed through a Circulator for
protection of the Tray from high VSWR
conditions. The Reject Port of the
Circulator provides a Reject Sample to
the Combiner Board which supplies the
Reflected Sample to the Dual Peak
Detector Board, Single Supply located in
the Tray that connects to the front panel
meter for monitoring purposes.
The 208/240 VAC Input to each Amplifier
Array Assembly connects to (A10) the AC
Distribution Assembly located on the
right side, center rear of the Cabinet.
The Assembly contains the Terminal
Block (TB1) to which the 208/240 Three
Phase or Single phase connects.
837B, Rev. 0 2-3
4-6 kW UHF Translator Chapter 2, System Description
Three phase connects, Line 1 to TB1-1A,
Line 2 to TB1-2A, Line 3 to TB1-3A and
Safety Ground to TB1-4A.
Single phase connects, Line 1 to TB1-1A,
Line 2 to TB1-3A and Safety Ground to
TB1-4A.
The AC Distribution Panel contains nine
Circuit Breakers that supply the AC to the
rest of the Amplifier Assembly. The
Input AC from TB1B is connected to
(CB1) the Main AC Circuit Breaker (55
Amps three phase or 100 Amps single
phase) that distributes the 208/240 VAC
to the other eight circuit breakers. The
output of CB1 has three MOVs, VR4 from
Line 1 to ground, VR6 from Line 2 to
Ground and VR3 connected across the
two lines for surge and over-voltage
protection. The switched Input AC is
wired through the Circuit Breakers, CB2CB7, via AC Line Cords to the six UHF
Amplifier Trays, LDMOS mounted in each
Amplifier Array Cabinet. CB2 is a 20
Amp Circuit Breaker that supplies the AC
voltage to the (A1) UHF Amplifier Tray.
CB3 is a 20 Amp Circuit Breaker that
supplies the AC voltage to the (A2) UHF
Amplifier Tray. CB4 is a 20 Amp Circuit
Breaker that supplies the AC voltage to
the (A3) UHF Amplifier Tray. CB5 is a 20
Amp Circuit Breaker that supplies the AC
voltage to the (A4) UHF Amplifier Tray.
In a 5kW configuration, CB6 is a 20 Amp
Circuit Breaker that supplies the AC
voltage to the (A5) UHF Amplifier Tray.
In a 6 kW configuration, CB7 is a 20 Amp
Circuit Breaker that supplies the AC
voltage to the (A6) UHF Amplifier Tray.
In 5 and 6 kW configurations, CB8 and
CB9 are 3 Amp Circuit Breakers that
supply AC to the two cooling fans
mounted in the Reject Load Assembly in
the Amplifier Array Assembly.
2.1.2.1 (A13) (Optional) External
Exhaust Kit (1061320)
Each of the 2-3 kW Amplifier Array
Assemblies may contain the (Optional)
(A13) External Exhaust Kit mounted on
the roof of the cabinets. This kit provides
greater cooling by venting the hot air
outside the Translator room using a
blower fan. +12 VDC is applied to TB14A in the Exhaust enclosure when the
UHF Exciter circuit breaker is switched
On. An Enable is connected to TB1-3A
when the UHF Exciter, Translator, is
switched to Operate. The Enable
energizes the Isolation Relay that applies
the 120 VAC to the fan that will operate.
2.1.3 Translator Output Assemblies
The outputs of the (A2 & A3) 2-3 kW
Amplifier Assemblies (+63.5 to +65.2
dBm) connect through (A5 or A6) 1-5/8”
to 3-1/8” Adapters to (A4) a Hybrid
Combiner. The combiner combines the
output from each Amplifier Assembly into
a single output. The Reject Output of the
Hybrid Combiner is connected through
(A12) a 1-5/8” to 3-1/8” Adapter to (A7)
a Directional Coupler (1016-1043) that
provides a Reject Sample from J3 to the
Metering Panel located in the UHF Exciter
Assembly for monitoring purposes. The
output of the Directional Coupler
connects to (A8) a 2500 Watt Reject
Load which dissipates any reject due to
problems in one of the Amplifier Arrays.
Mounted on the 2500 Watt Load is (A8A1) a Thermal Switch that connects to
the Overtemperature Fault circuit located
on the Transmitter Control Board in the
UHF Exciter Tray. If the temperature of
the load reaches 155°F. the switch closes
and causes an Overtemperature Fault to
occur which shuts down the Translator.
The output of the Hybrid Combiner at J3
is fed through 3-1/8” hard line to (A9) a
Bandpass Filter, (A10) an Output Trap
Filter Assembly, then to (A11) the Output
Coupler Assembly and finally to the
Antenna for your System. The Bandpass
Filter and Trap Filter are tuned to provide
high out of band rejection of unwanted
generated products. The filtered signal is
connected to (A11) an Output Coupler
Assembly that provides a Combined
Forward and a Combined Reflected Power
837B, Rev. 0 2-4
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