User's Manual
Table Of Contents
- 1 MXI101V AMPLIFIER–INTRODUCTION
- 2 SAFETY NOTICES
- 2.1 Beryllium Oxide Warning
- 2.2 Other Toxic Materials
- 2.3 Dangerous Voltages
- 3 LARCAN PARTS, ASSEMBLIES, ASSEMBLY DRAWINGS AND SCHEMATIC NUMBERS
- 1 MXi CONTROLLER
- 2 AMPLIFIER INSTALLATION AND STARTUP
- 3 TEST AND TROUBLESHOOTING
- 4 MAINTENANCE
- 5 SERVICE
- 6 TEST EQUIPMENT SETUP
- 7 SPECIFICATIONS
- 1 MXi VHF AMPLIFIER
- 1 FUNCTIONAL DESCRIPTION:
- 2 RF PREAMPLIFIER
- 3 POWER AMPLIFIER:
- 4 ADJUSTMENT OF BIAS VOLTAGE TO ESTABLISH PROPER QUIESCENT FET BIAS CURRENT:
- 6 LOW POWER SWEEP AMPLIFIERS
- 1 MXi POWER SUPPLY LAR1000-50-P5337
- 2 POWER SUPPLY DATA SHEET REPRINT
MXiV DUAL PALLET OPERATIONS AND MAINTENANCE
• Push the Front Panel ON/OFF button so that it is NOT pushed in.
2.4
2.4.1
AMPLIFIER ON SEQUENCE
Upon depressing the ON button, the fans start and at the same time the +50V power supply is enabled, thus
applying power to the MXi Amplifier. Since the Exciter or Channel Processor is on hot standby (RF is always
applied), the amplifier normally produces output power immediately.
Turning ON MXi Amplifier
1. Enable amplifier LOCAL operation by pressing the REM touch button such that the REM legend is NOT lit.
• Push the front panel ON button.
• The MXi Amplifier should now be ON.
Figure 10 Transmitter ON
2. Monitor the +50V power supply voltage and current on the LCD. Check that the power supply is operating by
pressing the P/S touch button. The voltage reading should be about 50V and the current should be about
3.0A under Static condition (no RF drive).
ALLOW THE AMPLIFIER SOME WARM-UP TIME!
Only after the transmitter has been ON for approximately 15 minutes should you perform the fine
adjustments. The amplifier must be allowed to reach its operating temperature for stable and consistent
operation. The Power Amplifier in the MXi transmitter is equipped with thermal compensation circuits, which
reduce the output power when the temperature rises. Therefore, the operating temperature must be reached
before adjusting the RF level to its proper level. The amplifier is also equipped with Automatic Gain Control,
primarily designed to prevent the transmitter from overpower or overdrive condition.
3. Increase the RF output by slowly turning the Exciter or Channel Processor output level control.
Stop at about 50% output power indicated on the LCD. At this level, the current should not be more than 6
Amps.
4. If the current is not abnormally high, increase the power to 100%. Again, make note of the PS current reading.
This should not be more than 18 Amps.
5. AGC SETTING: With the AGC still disabled, increase the output power to 110%, using the output level control
in the Exciter or Channel processor. Enable the AGC by pressing the AGC touch button until it lights. Use the
LOWER button to set the power to 100%.
6. With the amplifier fully functional and adjusted to its final setting, record keeping becomes very important.
Record the current, voltage, power, etc. This data can be used as a very valuable troubleshooting tool later.
Below is typical test data pertaining to the MXi amplifier at 100% output power.
TYPICAL DATA read on the LCD
FWD 100% CUTB 0.1V
RFL 00.1% PS VOLTS 50.0V
AGC 1.0V PS CURR 16A
TSM21Q-365 Rev 0 July 17, 2009 MXiV Dual Pallet Operations and Maintenance 16