Data Sheet

ManualsBrandsUBS-Axcera ManualsElectronics6000-Watt UHF Transmitter

835A 4 kW, 5 kW or 6 kW UHF Transmitter Set Up and Operation Procedure

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Initially the Transmitter should be turned on with the RF Output at J2 of the (A11) Coupler Assembly terminated into a

dummy load of at least the power rating of the Transmitter. If a load is not available, check that the Output of the Coupler

Assembly at J2 is connected to the Antenna for your System.

If your Transmitter contains the Receiver Option, it provides the operator the ability to select either the Combined IF Output

from the Receiver Tray or from the Modulator. The switching of the IF Relay, located on the ALC Board, is accomplished by

applying or removing a jumper on Jack J8 Pins 10 & 11 located on (A9) the Remote Interface Assembly. 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.

Connect the On Channel RF Signal Input to the "N" Connector Jack (J1), for 50Ω Input, or to the "F" Connector Jack (J3), for

75Ω Input, located on (A9) the Remote Interface Assembly, mounted on the top, rear of the cabinet. With Receiver selected,

the Transmitter uses the IF Output from the Receiver Tray.

Connect the Baseband Balanced Audio Input to the Terminal Block (TB1) located on (A9) the Remote Interface Assembly,

mounted on the top, rear of the Single UHF Exciter Cabinet. If Composite Audio, Stereo, is used instead of Balanced Audio,

connect the Composite Audio Input to the BNC Jack (J6). Connect the Baseband Video Input to the BNC Jack (J2) also

located on (A9) the Remote Interface Assembly.

Switch On the Main AC Circuit Breaker located on the AC Distribution Assembly mounted toward the rear of the Single UHF

Exciter Assembly. Switch On the Main AC Circuit Breakers located on the AC Distribution Assemblies mounted toward the

rear of the Amplifier Cabinets. Switch On the CB2-CB6 Circuit Breakers, for the individual UHF Amplifier Trays, on the AC

Distribution Assemblies mounted in each Amplifier Cabinet.

Switch the Operate/Standby Switch located on the UHF Exciter to Standby and the Auto/Manual Switch also on the UHF

Exciter to Auto. Normal operation of the Transmitter is with the switch in Automatic. Automatic operation of the Exciter uses

the Video Input to the Exciter as an Operate/Standby Switch. In Auto, if the Input Video is lost, the Exciter will automatically

revert the Transmitter to Standby and when the Video Signal is restored, the Exciter will automatically return the Transmitter

to Operate.

Move the Operate/Standby Switch on the Exciter to Operate. Note the power supply readings on the front panel Meters of the

UHF Amplifier Trays in each Amplifier Cabinet Assembly, they should be +26.5 VDC. Note: If the Transmitter does not

switch to Operate, when the Operate/Standby Switch is switched to Operate, check that there is an External Interlock Plug

connected to Jack (J7), located on the Remote Interface Assembly mounted in the top, rear of the Single UHF Exciter Cabinet,

and that it has a Jumper from Pins 1 to 2 which provides the interlock for the Exciter. The Interlock must be present for the

Transmitter to Operate.

Observe the Front Panel Meter located on the Metering Panel with the switch in the Combined Visual Output Power position,

it should read 100%. If needed, adjust the Power Adjust screwdriver pot located on the front panel of the UHF Exciter to

attain 100% Output on the Front Panel Meter located on the Metering Panel with the switch in the Combined Visual Output

Power position.

As you are checking the output Power Level, check the Meter Readings on the Transmitter Metering Panel in the % Reflected

Power Position for the Side A and also the Side B Amplifier Assemblies and the Combined position for the Transmitter. If the

% Reflected Power for any of the readings is very high, above 20%, a problem with the Output Coaxial Lines in the problem

Side Amplifier Assembly or in the Output Lines for the System is present and needs to be checked and corrected. A center

bullet missing from the 1-5/8" or 3-1/8" Rigid Coax Lines or loose bolts on the connections can cause this problem. Return the

Operate/Standby Switch to Standby.

Observe the % Exciter Power reading of the Meter on the Exciter, it should read the same as written on the Test Data Sheet for

your Transmitter. Move the Operate/Standby Switch, located on the Exciter, to Standby.

The Gain and Phase controls located on the front panels of the individual UHF Amplifier Trays were adjusted at the factory to

attain 100% Output of the Transmitter and should not need readjusted. The Forward Meter readings for Side A and for Side B

may not be the same but should be the same as the values written on the Test Data Sheet for your Transmitter. Side A and Side

B are combined to give the correct Peak of Sync Output, which is 100% in the Combined Visual position.

Summary of content (2 pages)

PAGE 1
835A 4 kW, 5 kW or 6 kW UHF Transmitter Set Up and Operation Procedure Initially the Transmitter should be turned on with the RF Output at J2 of the (A11) Coupler Assembly terminated into a dummy load of at least the power rating of the Transmitter. If a load is not available, check that the Output of the Coupler Assembly at J2 is connected to the Antenna for your System.
PAGE 2
835A 4 kW, 5 kW or 6 kW UHF Transmitter Set Up and Operation Procedure The readings on each of the individual UHF Amplifier Trays may not be the same. Refer to the Test Data Sheet for your Transmitter and compare the final readings from the Factory on the Test Data Sheet with the readings on each of the Trays after the Set Up. They should be very close to the same.