System Description

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835A 4 kW, 5 kW or 6 kW UHF Transmitter System Description

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The 835A is a complete UHF Solid State Internally Diplexed Television Transmitter which operates at a nominal Visual

Output Power for a 4 kW of 4000 Watts Peak of Sync and Average Aural Output Power of 400 Watts, at an A/V Ratio of 10

dB, 10 % Sound or 200 Watts at 13 dB, 5 % Sound, or for a 5 kW, 5000 Watts Peak of Sync and Average Aural Output Power

of 500 Watts, at an A/V Ratio of 10 dB, 10 % Sound or 250 Watts at 13 dB, 5 % Sound, or for a 6 kW, 6000 Watts Peak of

Sync and Average Aural Output Power of 600 Watts, at an A/V Ratio of 10 dB, 10 % Sound or 300 Watts at 13 dB, 5 %

Sound. The 835A is made up of three Cabinets, a UHF Single Exciter Cabinet and two Amplifier Array Cabinets.

The standard 835A is functionally comprised of (A1) a Single UHF Exciter Assembly, (A2 & A3) two Amplifier Array

Assemblies, (A4) a Hybrid Combiner Assembly, (A9) a Bandpass Filter , (A10) an Output Trap Filter Assembly and (A11) an

Output Coupler Assembly. A sample is taken from the Hybrid Combiner and connected to (A7) a Directional Coupler .

The (A1) Single UHF Exciter Assembly contains (A1) a UHF Exciter Tray, (A3) a Splitter, (A4 & A5) two Variable

Phase/Gain Trays (1245-1200), (A6) a Metering Panel, (A8) an AC Distribution Assembly, Exciter (1245-1500) and (A9) a

Remote Interface Assembly (1245-1801). This Exciter also contains a UHF Receiver Tray (1265-1100).

The (A2 & A3) 2-3 kW Amplifier Array Assemblies (1278-1300) each contain (A9-A1) an 8 Way Splitter (ZFSC-8-43), in a 4

kW four (A1, A2, A3 & A4), in a 5 kW five (A1, A2, A3 A4 & A5) and in a 6 kW six (A1, A2, A3 A4, A5 & A6) UHF

Amplifier Trays, (A7) a 4, 5 or 6 Way Combiner, (A8) an Output Coupler, (A10) an AC Distribution Assembly for 3 Phase

(1278-1100) or for Single Phase (1278-1200) and (A11) an Interface Panel. The reject output from the Combiner Board

connects to (A12-A2) the Combiner Reject Load Board.

(A1) Single UHF Exciter Assembly

The Single UHF Exciter Assembly contains (A1) a UHF Exciter Tray (1245-1100) which 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 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.

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 which

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 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. To select the output from the Modulator, J8-10 and 11, must be connected together.

The Exciter RF Output of the (A1) UHF Exciter at J15 is connected to the S Input on (A3) the Splitter.

The Output of the UHF Exciter is split two ways by A3 with the RF Output #1 connected to the input of the (A5) Variable

Phase/Gain Tray (1245-1200) and the RF Output #2 connected to the input of the (A4) Variable Phase/Gain Tray (1245-1200).

The output of the (A4) Variable Phase/Gain Tray connects to (A2) the Side A 2-3 kW Amplifier Array Assembly (1278-1300).

The output of the (A5) Variable Phase/Gain Tray connects to (A3) the Side B 2-3 kW Amplifier Array Assembly (1278-

1300).

(A2 & A3) 2-3 kW Amplifier Array Assemblies (1278-1300)

The (A2 & A3) Amplifier Array Assemblies are identical, with each Assembly containing (A9-A1) an 8 Way Splitter (ZFSC-

8-43), four for 4 kW (A1, A2, A3 & A4), five for 5 kW (A1, A2, A3, A4 & A5) or six for 6 kW (A1, A2, A3, A4, A5 & A6)

UHF Amplifier Trays, (A7) a 4, 5 or 6 Way Combiner, (A8) an Output Coupler (1016-1043) and (A10) an AC Distribution

Assembly for 3 Phase (1278-1100) or for Single Phase (1278-1200). The reject output from the 4, 5 or 6 Way Combiner

Board connects to (A12-A2) the Combiner Reject Load Board (1278-1311).

Summary of content (4 pages)

PAGE 1
835A 4 kW, 5 kW or 6 kW UHF Transmitter System Description The 835A is a complete UHF Solid State Internally Diplexed Television Transmitter which operates at a nominal Visual Output Power for a 4 kW of 4000 Watts Peak of Sync and Average Aural Output Power of 400 Watts, at an A/V Ratio of 10 dB, 10 % Sound or 200 Watts at 13 dB, 5 % Sound, or for a 5 kW, 5000 Watts Peak of Sync and Average Aural Output Power of 500 Watts, at an A/V Ratio of 10 dB, 10 % Sound or 250 Watts at 13 dB, 5 % Sound, or for a 6 k
PAGE 2
835A 4 kW, 5 kW or 6 kW UHF Transmitter System Description (A2 & A3) 2-3 kW Amplifier Assemblies (1278-1300) - Continued The RF Input 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 which splits it eight ways. The outputs connected to J1, the RF Input Jack on each of the UHF Amplifier Trays or are terminated with 50Ω.
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835A 4 kW, 5 kW or 6 kW UHF Transmitter System Description the UHF Amplifier Trays. Control and Status - Continued When the UHF Exciter is in Operate, the Green LED (DS2) is On and when in Standby the Amber LED (DS1) is On. Note: If the Transmitter does not switch to Operate when S1 is switched to Operate, check that a dummy plug, with a Jumper between Pins 1 & 2, is connected to Jack J7 located on (A9) the Remote Interface Assembly in the Single UHF Exciter Assembly.
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835A 4 kW, 5 kW or 6 kW UHF Transmitter System Description Main AC Input - Continued 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 TB1-1, Line 2 to TB1-3 and Safety Ground to TB1-2.