User's Manual

PINEAPPLE TECHNOLOGY, INC.
UTX5K ULTRA-2 Operating and Service Manual
V -- THEORY OF OPERATION
(CONTINUED) Page 2 of 5
D. ADP500 AND PAS6 PERFORMANCE MONITO
R
The ADP500 and PAS6 Performance Monitor provides the following functions:
1. Monitors FORWARD AND REFLECTED POWER to the hybrid combiner 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. 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.
3. Provides current monitoring of all the pallets used in the six (6) 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 PAS6. In normal operation,
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 PAS6. The ADP500 will now display status of each pallet in that PA. The multi-meter will read
the actual current.
4.
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.
5.
A
n RF MONITOR port (BNC) is available to connect a spectrum analyzer for monitoring the
output signal.
6. METER SELECTION SWITCHES
The PAS6 is used to select the appropriate PA Module (PA1K) for performance display on the ADP500.
PA designations are PA1 starting from the top row going left to right with PA6 located on the bottom (3rd)
row down on the right side when viewed from the front of the transmitter rack.
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
Typical reading SMPTE BARS 2-3 A for PA5
PA6……………………………………………
…
No Connection
PS VOLTS……………………………………
…
Reads DC voltage applied to PA stages
Typical reading would be +29 to 33 VDC
P FWRD………………………………………
…
Reads PA output power in P-Sync percentage of rating
Full power reading would be 100%
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