User's Manual
PINEAPPLE TECHNOLOGY, INC.
UTX2.5K ULTRA Operating and Service Manual
V -- THEORY OF OPERATION
(CONTINUED) (Page 2 of 5)
The power modules are "HOT PLUGGABLE" and can be removed or installed without turning off the
transmitter.
Each power supply module 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 FOR MODEL # TWRI6004 PROVIDED WITH THE UTX2.5K ULTRA.
D. ADP500 AND PAS3 PERFORMANCE MONITO
R
The ADP500 AND PAS3 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 (5% 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 shut down. The front panel LED will change
from green to red in case of a fault.
4. Provides current monitoring of all the pallets used in the three (3) PA1K 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 PAS3. In normal operation, a
PA FAULT is indicated by going from green to read. RED indicates that the current level is below 500 ma
and a transistor may have failed. To read the actual current, select the appropriate PA Bank using the
PAS3. The ADP500 will 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 diagonostic purposes. When activated, this switch allows
the technician to monitor the bias currents for each pallet. These readings were recorded at the factory
and are found on the Transmitter Test Report, DC Test Report Section. This is the best way to
troubleshoot possible transistor 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 TTL 0 state and the output power
has been reduced to near zero.
6.
A
n RF MONITOR port (BNC) is available to connect a spectrum analyzer for monitoring the
output signal.
7. METER SELECTION SWITCHES
The PAS3 is used to select the appropriate PA module (PA1K) for performance display on the ADP500.
PA designations are PA1 starting from the top row left (there is no PA located in the top row right
position) with PA3 and 4 located on the bottom row left to right.
The rotary switch on the ADP500 is the detail selector for the multi-meter. The various positons are
defined as follows:
PA1 thru PA5…………………………………
…
Reads PA Pallet currents as selected
Typical reading in INHIBIT MODE 1.5 to 2.5 A
Typical reading SMPTE BARS 5-7 A for PA1 thru PA4 with normal picture
Typical reading SMPTE BARS 2-3 A for PA5 with normal picture
Page 8