UBS Axcera 835A-6 6000-Watt UHF Transmitter User Manual 281872

UBS-Axcera 6000-Watt UHF Transmitter 281872

Meters Switches Indicators

835A 4 kW, 5 kW or 6 kW UHF Transmitter Meters, Switches, Indicators and Samples
Name Function
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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.
835A 4 kW, 5 kW or 6 kW UHF Transmitter Meters, Switches, Indicators and Samples
Name Function
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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.
835A 4 kW, 5 kW or 6 kW UHF Transmitter Meters, Switches, Indicators and Samples
Name Function
- Page 3 of 3 -
UHF Amplifier Trays- Continued
Status Indicators
Overdrive (DS2 Red) Indicates that the level of the drive to the output amplifiers is too high. The
protection circuit will limit drive to the set threshold. The Fault is generated on
the Amplifier Control Board.
VSWR Cutback (DS1 Red) Indicates that Reflected Power Level of the Tray has increased above 50% which
will automatically cutback the Output Power Level to 50 %. The Fault is
generated on the Amplifier Control Board.
Overtemperature (DS3 Red) Indicates that the temperature of (A5-A6-A3 & A5-A6-A4) one or both of two
Thermal Switches mounted on the heatsink assembly for the output amplifiers is
above 175° F. When this Fault occurs the Enable to the Switching Power Supply
in the effected Amplifier Tray is removed immediately.
Sample
Module O/P (0 dBm) A Sample of the Combined Output of the four Dual Stage Amplifier Boards
taken from the Dual Peak Detector Board.
Variable Phase/Gain Trays
Meters
Switch (S1), Meter Selects the desired % Power or the ALC Voltage reading.
% Output Power Reads the % Output Power of the Tray. (100% = +23 dBm pk of Sync + Aural)
ALC Reads the ALC Voltage, from the UHF Exciter, which connects to the Amplifier
Trays.
Sample
Output (J4), (0 dBm) A front panel Sample of the RF Output of the Phase/Gain Tray which connects to
the Amplifier Array, taken from the Variable Gain/Phase Board.

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