Control/Interface Board Interface (PC4J10)
Jack – Pin #
Function
2
6
24
J1 – 26
AMPL STATUS LED: A high or low voltage at this pin originates from A1J3-3
to signal the status of the transistors within the 2W UHF Amplifier module. A
high at PC4J6-3 and PC4U3A-3 indicates that the amplifier devices are
operating properly while lighting AMPLIFIER STATUS LED DS1 via PC4R8,
PC4J10-26 and Q1. A low at the output of PC4U3A indicating a device failure
within the 2W Amplifier will extinguish the front panel AMPLIFIER STATUS
indicator DS1 via the same path.
2.2k
28V/15V/5V Power Supply:
Integrated Power Design SRW-65-4006-28
t
A2PS1
Input:
TB1-L/N/G
85-264Vac / 47-63Hz / 128W
Outputs: TB2-1
15V @ 2A Max.
TB2-4
+15V @ 2A Max.
TB2-6
+28V @ 1A Max.
TB2-9 & 10
+5V @ 5A Max.
PS1 is a very compact, multioutput switching power supply capable of providing 65 watts of
maximum total output. It features a universal input with output overvoltage and overcurrent
protection. This supply powers all of the modules and PC boards within the Exciter drawer and is
not adjustable or field repairable. If found defective, PS1 must be returned to EMCEE for repair
or replacement.
2.3
500W UHF POWER AMPLIFIER DRAWER:
Interconnection Diagram 30394008/Rev 54
t
A3
Frequency Response
470-806MHz
RF In (J1)
+18dBm peak visual
RF OUT (J2)
+58dBm peak visual
Gain (J1-J2)
40dB +1/
2dB
The TTU500FA transmitter is made up of one 500W Power Amplifier drawer (A3) containing two
300W Power Amplifier assemblies mounted on 14 by 16 inch fabricated high density heat sink
material. Both heat sink assemblies amplify an equal portion of the divided signal from Splitter
CP1 and provide approximately 300 watts of peak visual power at their outputs. Each assembly,
powered by dedicated, redundant 32V power supplies (PS1/PS2), includes two driver stages
composed of dual parallel LDMOS transistors and a final stage built with four parallel high power
LDMOS devices. The first driver (Q1/Q3) is a Class A amplifier capable of 4 watts of peak visual
power and 18dB of gain. The second amplifier (Q5/Q6) is a Class AB driver delivering 14dB of
gain and a 40 watt peak capability. The final stage, providing 14dB of gain, is composed of four
120 watt devices (Q7/Q8/Q9/Q10) designed in a parallel push-pull configuration. The outputs of
the two 300 Watt Amplifier assemblies are summed in Combiner CP2 before exiting the drawer
at RF OUTput J2. The drawer’s monitoring circuits used to detect amplifier and power supply faults