C3.18 T854 Initial Tuning and Adjustment M8SL2-00-002-812
© Copyright Tait Electronics Limited August 2004. All rights reserved.
Reverse alarm
1. Connect the power meter to the transmitter output.
2. Key up the transmitter and set the output power level to the operational output
level.
3. Replace the power meter with the appropriate valued open ended attenuator. This
should generate the desired return loss/reflected power for the desired high
reverse power alarm threshold point.
4. Adjust the “Rev-alarm adjust” preset until the alarm LED just comes ON.
5. Turn the transmitter OFF.
3.10.2 T800-10-0520 Tx-Alarm/Channel-Select Kit
When fitted to a T854 transmitter, the T800-10-0520 Tx-Alarm/Channel-Select plug-in
board provides the following features:
• The plug-in board monitors the transmitter’s output power, and generates a
low forward-power and/or high reverse-power alarm as appropriate.
• The plug-in board also includes channel select switches that enables the user to
manually set the operational channel of the T854.
The plug-in board provides the same alarm outputs as the T1500-52-0000:
• Forward Power Alarm: Aux D-range pin 13
• Reverse Power Alarm: Aux D-range pin 14
Note: AUX-OUT-0 is disabled when the plug-in board is installed.
The Tx-Alarm function is achieved by comparing the output voltages of the transmit-
ter’s directional coupler to user-defined reference levels.
The low forward-power alarm output is gated with the Tx-Enable input, to ensure that
no alarm is generated when the transmitter is not transmitting. The high reverse-power
alarm is not gated.
Note: The plug-in board does not require additional wiring. It can be set up on the
bench. This is possible because the Tx-Enable line is accessed from inside the
T854, rather than from the backplane PCB (as on the T1500-52-0000).
Parts Supplied
T800-10-0520 Tx-Alarm/Channel-Select Kit should contain the following:
• T800-10-0520 plug-in board
To Next Page
Loading...
Need help?
General
