Pineapple Technology VTX2KW-A, Инструкция по эксплуатации, Страница: 8 / 49

PINEAPPLE TECHNOLOGY, INC.
VTX2KW-A Operating and Service Manual
15. Using the ADP500 reflected power indication check the LOAD reflected power. This should be less
that 5% reflected.
16. Return to the PA current readings on the ADP500 to verify that all the currents are approximately
the same.
17. With successful performance t
o
step 17, the transmitter output power can be increased using the
output level adjustment on the modulator to achieve 100%. The aural power can be added at this time
not exceeding 10% of output p-sync power as indicated on the ADP500.
V — THEORY OF OPERATIONS
A. INTRODUCTION
The VTX2KWA transmitter was designed to meet or exceed all FCC applicable specifications for TV
Broadcast Equipment. Special attention was given to the selection of sub-assemblies and components to
achieve maximum reliability and minimum down time. The construction of the VTX2KWA is BASIC
and MODULAR with most components field replaceable. Special emphasis was placed on KEEPING IT
SIMPLE and returning to more traditional transmitter layouts and instrumentation.
This transmitter was designed for Analog (NTSC) transmission with provisions and options available to
convert to Digital Service when necessary.
Refer to the VTX2KWA block diagram (page 12) for an overview of the transmitter architecture. The key
subassemblies are listed below followed by a brief description. This will give the technician basic infor-
mation needed to understand the operations of the transmitter and the function of each subassembly.
SEE SECTION VI.A FOR PARTS LIST (page 13)
B. ACDIS2 AC & DC DISTRIBUTION
The ACDIS2 is the primary AC power inlet module. The VTX2KWA transmitter was designed to except
208 to 240 V AC SINGLE PHASE using a FOUR (4) wire connection. The four wires are
2 wires for 208-240V AC single phase
1 wire for neutral connection
1 wire for safety ground connection
CAUTION: Connection to the AC Primary Source must be made using all four wires listed above.
Follow the wiring instruction given in the AC WIRING section III. 3 (page 5). If not followed, severe
damage to the transmitter and or electrical shock is possible.
The ACDIS2 performs the following functions:
1. Provides a primary AC power breaker point to shutdown the transmitter.
2. Provides 208 VAC single phase power to each of the
2
KW DC power supplies with individual breaker
points for added safety.
3. Provides 110 VAC circuits for Modulator, ADP500, Auxiliary Power Source, and AUX Power where
needed.
V — THEORY OF OPERATIONS
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