UBS Axcera 835A-6 Meters Switches Indicators

835A 4 kW, 5 kW or 6 kW UHF Transmitter Meters, Switches, Indicators and Samples

Name

Function

Receicer Tray (Optional)

Samples - BNC Connectors mounted on front panel.

f(IF) Output A Sample of the IF Output taken from the IF Filter/ALC Board.

f(s) Oscillator A Sample of the Channel Oscillator Output taken from the Sample Jack of the

Channel Oscillator Assembly.

UHF Exciter Tray

Meters

Meter (A1-A18) Reads power in terms of a percentage of the calibrated Output Power level. A

full scale reading is 100% which is equivalent to the full rated Peak of Sync
Exciter Output Power. Also reads Audio, Video and ALC reading.

Switch (S3), Meter Selects the desired % Exciter Power, Video, or Audio Levels or the ALC Voltage

reading.

Audio Reads the Audio Level. (±25 kHz Balanced or ±75 kHz Composite)
(0-100 kHz)

ALC Reads the ALC Voltage Level. (.8 VDC Typical)
(0-1 V)

% Exciter Reads the % Exciter Output Power. (Level needed to attain
(0-100) 100% Output Power)

Video Reads the Video Level. (1V = 140 IRE)
(0-1 V)

Switches

Transmitter (S1) The momentary switch (S1) applies a ground to K1, a latching relay, located
Operate/Standby on the Transmitter Control Board. K1 will switch either to Operate or to Standby

depending on which direction S1 is pushed. When switched to Operate, a low,
Enable Command, is applied to each Amplifier Array which are split and
connected to each Amplifier Tray. These Enables turn on the UHF Amplifier
Trays. The opposite occurs when switched to Standby.

Mode Select (S2) The momentary switch (S2) applies a ground to K2, a latching relay, located
Auto/Manual on the Transmitter Control Board. K2 will switch the Transmitter to Automatic

or Manual depending on which direction S2 is pushed. In Automatic, the Video
Fault Command from the ALC Board will control the Operation of the
Transmitter. The Transmitter will switch to Standby, after a slight delay, if the
input video is lost and will switch back to Operate, quickly, when the Video is
restored. In Manual, the Transmitter is controlled by the Operator using the front
panel Operate/Standby Switch or by remote control.

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835A 4 kW, 5 kW or 6 kW UHF Transmitter Meters, Switches, Indicators and Samples

Name

Function

UHF Exciter Tray - Continued

Fault Indicators

Video Loss (DS9 Red) Indicates that the Input Video has been lost to the Transmitter. The Fault is

generated on the ALC Board located in the UHF Exciter Tray.

VSWR Cutback (DS7 Amber) Indicates that Reflected Power Level of the Transmitter has increased above 20%

which will automatically cutback the Output Power Level to 20 %. The Fault is
generated on the Transmitter Control Board located in the UHF Exciter Tray.

Samples

f(IF) A Sample of the Visual IF taken from the Sample Jack on the IF Carrier Oven

Oscillator Board.

f(IC) A Sample of the 4.5 MHz Intercarrier taken from the Aural IF Synthesizer Board.

f(s) A Sample of the Channel Oscillator Output taken from the Sample Jack of the

Channel Oscillator Assembly.

Exciter O/P An Output Power Sample of the Exciter taken from the UHF Upconverter Board.

Transmitter O/P A Forward Power Sample of the Transmitter taken from the Visual/Aural

Metering Board.

UHF Amplifier Trays

Meters

Meter (A9) Reads power in terms of a percent of the calibrated power output value. A full

scale reading is 100% which is equivalent to the full rated Peak of Sync Visual
Output Power + Aural (600 Watts). Also reads Power Supply and AGC Voltage.

Switch (S2), Meter Selects the desired % Power or the Voltage reading.

% Output Pwr Reads the % Output Power of the Tray. (100% = 600 Watts pk of Sync + Aural)

% Refl (Reflected) Reads the % Reflected Output Power of the Tray. (<5% with all Amplifier Trays

operating)

Power Supply Reads the Power Supply Voltage. (+26.5 VDC)

AGC Voltage Reads the AGC Voltage Level. (1-2 VDC Typical)

Status Indicators

Enable (DS4 Green) Indicates that an Enable, Operate Command, is applied to the Trays from the

UHF Exciter Tray.

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