User's Manual

Digital UHF Transmitter Chapter 4, Circuit Descriptions
DT835A, Rev. 1 4-45
and CB7 are 20 Amp Circuit Breakers
that are added to the AC Distribution
Assembly when the two extra UHF
Amplifier Trays are needed for the 5
kW and 6 kW Transmitters. CB6 is a
20 Amp Circuit Breaker which protects
the AC connected through J5 on the AC
Distribution Assembly to J4 on the (A5)
UHF Amplifier Tray. CB7 is a 20 Amp
Circuit Breaker which protects the AC
connected through J6 on the AC
Distribution Assembly to J4 on the (A6)
UHF Amplifier Tray.
4.10 (A10) AC Distribution
Assembly, Three Phase (1278-
1100; Appendix C)
The AC Distribution Assembly, 3 Phase
AC Input distributes the Main AC Input,
208/240 VAC 3 Phase @ 55 Amps, that
connects to the individual Trays in the
Amplifier Cabinet which make up the
Amplifier Array.
The 208/240 VAC 3 Phase Main AC
Input to the Amplifier Cabinet connects
to the Terminal Block TB1, Line 1 to
TB1-1A, Line 2 to TB1-2A, Line 3 to
TB1-3A and Safety Ground to TB1-4A.
The 208/240 VAC Main AC Input is
wired from the Terminal Block TB1-1B
(Line 1) to the 55 Amp Circuit Breaker
CB1-1, TB1-2B (Line 2) to the Circuit
Breaker CB1-3, TB1-3B (Line 3) to the
Circuit Breaker CB1-5 and TB1-4B
(Safety Ground) to Chassis Ground #1.
The switched Main AC Input is wired
from the Circuit Breaker to the up to six
20 Amp Circuit Breakers, CB2-CB7,
that distribute the AC to the up to six
UHF Amplifier Trays in the Amplifier
Array. The number of circuit breakers
is determined by the number of
Amplifier Trays which is determined by
the output power of the Transmitter in
which the Amplifier Assemblies are
used. Six MOVs, for surge and
transient protection, are connected to
the AC Lines from the Circuit Breaker,
VR4, VR5 and VR6 from the AC Lines to
Ground and VR1, VR2 and VR3 across
the AC Lines.
CB2 is a 20 Amp Circuit Breaker which
protects the AC connected through J1
on the AC Distribution Assembly to J4
on the (A1) UHF Amplifier Tray. CB3 is
a 20 Amp Circuit Breaker which
protects the AC connected through J2
on the AC Distribution Assembly to J4
on the (A2) UHF Amplifier Tray. CB4 is
a 20 Amp Circuit Breaker which
protects the AC connected through J3
on the AC Distribution Assembly to J4
on the (A3) UHF Amplifier Tray. CB5 is
a 20 Amp Circuit Breaker which
protects the AC connected through J4
on the AC Distribution Assembly to J4
on the (A4) UHF Amplifier Tray. CB6
and CB7 are 20 Amp Circuit Breakers
that are added to the AC Distribution
Assembly when the two extra UHF
Amplifier Trays are needed. CB6 is a
20 Amp Circuit Breaker which protects
the AC connected through J5 on the AC
Distribution Assembly to J4 on the (A5)
UHF Amplifier Tray. CB7 is a 20 Amp
Circuit Breaker which protects the AC
connected through J6 on the AC
Distribution Assembly to J4 on the (A6)
UHF Amplifier Tray.
4.11 (A12) Combiner Reject Load
Assembly (1278-1312)
NOTE: The Combiner Reject Load
Assembly is only used in the 2.5 and 3
kW Amplifier Arrays.
The Reject Load Assembly provides
connections to 6 loads to which the
reject outputs of the 6 Way Combiner
Board are cabled. The Assembly
consists of (A2) a Combiner Reject
Load Board (1278-1311), mounted on
a heatsink, two Thermal Switches (A1
& A4) and two Fans (A3 & A5).
If a miss-match due to a malfunction or
other problem occurs in the combining
process, the reject power is dissipated
in the load to which it is connected.