PINEAPPLE TECHNOLOGY, INC.
VTX2KW-A Operating and Service Manual
4. Analog metering is provided to monitor the Power supply voltage and current being applied to the RF
Amplifier stages
5. Power supply current sharing test points are provided for checking current sharing between power
supply modules.
SEE SECTION VI.B FOR SCHEMATIC AND PARTS LIST (page 14)
C. AC2008 2 KW POWER MODULE
The VTX2KWA transmitter is designed with over 8 KW of DC power available to the transmitter. To
achieve this level, the power supply is made up of four RR6000 (PTI P/N AC2008) power module
mounted into TWO mainframe assemblies RU2 (PTI P/N AC2009) which are capable of managing three
2 KW modules each.
The power modules are “HOT PLUGGABLE” and can be removed or installed without turning off the
transmitter.
Each power supply modules has OVER VOLTAGE, OVER CURRENT, AND OVER TEMPERATURE
protection as well as a fault signal in the event of a failure.
REFER TO MANUFACTURER’S MANUAL PROVIDED WITH THE VTX2KWA.
D. PAS10 & ADP500 PERFORMANCE MONITOR
The PAS10 & ADP500 PERFORMANCE MONITOR provides the following functions:
1. Monitors FORWARD AND REFLECTED POWER to the antenna and presents it as a percentage of
power rating. The transmitter comes set to 100% P-Sync power based on the ratings of the transmitter.
2. Monitors Aural Power as a percentage of P-Sync rating (10 % typical)
3. Provides a HIGH ANTENNA VSWR MONITOR In the event of an antenna or coax failure where the
reflected power exceeds 25% the transmitter will shutdown. Front panel LED with change from green
to red in case of a fault.
4. Provides current monitoring of all the pallets used in the six V600LDV2 power amplifier assemblies.
The current levels can be read directly from the multi-meter on the front panel. Individual pallets are
selectable on the ADP500 and the PA assemblies are selected using the PAS10. In normal operations, a
PA FAULT is indicated by going from green to red. RED indicates that the current level is below 500
ma and a transistor could have failed. To read the actual current, select the appropriate PA Bank using
the PAS10. The ADP500 will now display status of each pallet in that PA. The multi-meter will read
the actual current.
5. A PA INHIBIT switch is provided for failure diagnostic purposes. When activated, this switch allows
the technician to monitor the bias currents for each pallet. These readings should be recorded when the
transmitter is first installed and used as a reference. This is the best way to trouble shoot possible tran-
sistor problems. When in the PA INHIBIT mode, the RF PWR OFF LED will change from green to red
indicating that the “SHUTDOWN LINE” Is at a TTL 0 state and the output power has been reduced to
near zero.
6. An RF MONITOR port (BNC) is available to connect a spectrum analyzer
or other test equipment
for
monitoring the output
signal.
V — THEORY OF OPERATION
Page 8