User's Manual

PINEAPPLE TECHNOLOGY, INC.
DTC25U Operating and Service Manual
lV -- TRANSCODER TURN-ON PROCEDURE
lV --- TRANSCODER TURN-ON PROCEDURE (Page 1 of 3
)
See the previous section on installation before proceeding with this section. Improper installation of th
e
transcoder can cause serious damage to the equipment or operating personnel and may voi
d
manufacturers warranty. Initial turn on and check out is very important for the broadcast engineer t
o
learn how to setup and operate the transcoder. Following these steps will ensure long and reliable operation
:
1. Check the transcoder output load or antenna for proper installation and connection to the transcoder
.
2. Inspect the transcoder front and back to check for broken items or lose fitting items. These must
be replaced or properly secured before turning the transcoder on. Pay special attention to all R
F
connectors including transmit coaxial cable and antenna.
3. Check the AC breaker and on/off switches to ensure that all are in the OFF position.
4. Verify the switch on the power strip at the back of the cabinet and the power switch on the front of the
LTX Mainframe are in the OFF position. Plug in the AC power cord to a nearby 110 AC electrica
l
connector with associated, appropriately sized, circuit breaker.
5.
Verify the output power level on the Drake Upconverter is set to minimum ( GAIN fully CCW ). See Fig 1
below for location. On the LTX Mainframe verify
X
MTR switch is in STBY.
6. Refer to the transcoder and upconverter instruction manuals in the DTC25U User Manual to locate the key
functions and become familiar with the unit. Insure that all connections, including the DC power
connection and the RF (IF) connection, between the 8VSB Regenerator and Upconverter have been made.
7. Verify, using the front panel display on the transcoder upconverter, that the correct output channel has
been selected. At this time, no connection should be made to the transcoder input at the back of the unit.
Any following measurements will be done using the Null Packets generated inside the transcoder
.
8. Turn-on the switch located on the power strip at the rear of the DTC25U. Note: The Larcan Transcoder
will come on at this time as well as the cabinet fan. A green light indication should be seen on the Drake
Upconverter and, after a few minutes, the two green lights on the transcoder will turn red indicating proper
operation.
9.
Locate and turn on the front panel breaker found on the LTX Mainframe and set the
X
MTR switch
to the ON position.
MAKE THE FOLLOWING OBSERVATION
S
METER READINGS TYPICAL
DC SUPPLY VOLTAG
E
32 VDC
PA1 DRIVER CURREN
T
1.7 AMPS ± 20%
PA2 FINAL CURREN
T
2.7 AMPS ± 20%
PA3 FINAL CURREN
T
1.3 AMPS ± 20%
RF OUTPUT POWER 10 TO 50%
RFL'D POWER < 10%
NOTE STATUS LIGHT
S
FAN GREEN
TEMP GREEN
+DC GREEN
THE FAN SHOULD BE MAKING SOME NOIS
E
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