User Manual

MXi AMPLIFIER CONTROLLER BOARD REV.2
PUB06-82 Rev 1 July 17, 2007 06-82-31 MXi Amplifier Controller Board Rev.2
screen is the new baud that is not yet programmed. Note: The MXi will still operate at the original baud until the
new one is saved.
If the user presses the STOP menu button, then the number of stop bits in the serial format will toggle between
1and 2. The new desired number of stop bits will be displayed in the second line of the LCD within the 8B-1S-NoP
section where the stop bits will be either 1S or 2S in this string. At the same time, the NewFmt light on the third
line lights to indicate that a new serial format (Baud or Stop bits or both) is pending but not taken.
Once the operator is satisfied with the new Baud and Stop bits, pressing the SAVE button causes the MXi to
implement the new serial format. Pressing the CLR button abandons all selections and revert to the previous
Baud and Stop bits without any action taken.
4.5 POWER SUPPLY VOLTAGE AND CURRENT CALIBRATION
To set up the power supply voltage and current reading, the operator must enter the Power Supply submenu on
the LCD. The Power Supply submenu is entered by pressing the P/S submenu button on the main display.
This submenu displays the status, voltage and current for the 32V power supply. Each display item and control is
described as to its meaning and function.
The LCD displays a typical P/S submenu as follows:
Figure 19 Power Supply Submenu Screen
1. To set up the voltage reading, turn on the transmitter and verify that the power supply is indeed running.
Line two of the LCD should have the power supply as active, with all of the status lights in line #3 as true,
just as is shown in the above LCD screen.
2. With a voltmeter, measure the actual voltage from the power supply; this can be measured at pin 1 of J4.
3. Adjust potentiometer R14 until the displayed voltage equals that being measure by the voltmeter.
4. To set up the current reading, the power supply should be ON as in the above paragraph and enough RF
drive (at least 50%) should be applied to get a reasonable current level for calibration.
5. Use a clamp-on current Ampmeter to measure the current draw from the 32V power supply. If multiple
wires are being used to connect the power supply to the RF amplifier, insure that all of the wires are
included in the clamp-on meter. However, make sure that none of the ground wires are included (only the
+32V wires) or else the reading will be too low.
6. If the MXi is configured to measure the current with the onboard current sensor U9 via connector J4,
adjust potentiometer R15 until the displayed current agrees with that measured on the clamp on meter.
If an external power supply is used that has its own current telemetry sensing, it may have its own setup as well.
The current reading on the LCD will still be affected by R15 but the external supply may require its own
calibration, if the level it sends to the MXi is too low or high. A good level would be in the range of 2-4 volts for full
scale current.