Nautel FM10, Технические инструкции

Страница: 69 / 200

10 000 WATT FM BROADCAST TRANSMITTER
FM10
Page 4-6
01 October 2002
(d) Simultaneously monitor the
DC SUPPLY
VOLTAGE , DC SUPPLY CURRENT
and
FORWARD/REFLECTED POWER
meter
indications and press the
OUTPUT POWER
RAISE
switch until the
DC SUPPLY VOLTS
meter indication is 20.0 volts.
Stop adjustment in an increasing direction if the
current indication on the
DC SUPPLY CURRENT
meter exceeds 65 amperes or if the forward power
indication on
FORWARD/REFLECTED POWER
meter's upper scale exceeds 2500 watts or if it does
not indicate any forward power.
(e) The forward power indication on the
FORWARD/REFLECTED POWER
meter's upper
scale should be between 2100 and 2400 watts
but must not exceed 2500 watts.
NOTE
The forward power indication for a specific PA
voltage will stay relatively constant across the FM
frequency band.
(f) The total current indication on the
DC SUPPLY
CURRENT
meter's upper scale should be
between 49 and 64 amperes but must not
exceed 65 amperes.
NOTE
The total current indication for a specific forward
power will differ across the FM frequency band. It
may be lower at the lower frequencies and higher at
the higher frequencies.
(g) Set the
FORWARD/REFLECTED POWER
switch
to
REFLECTED
.
(h) The reflected power indication on the
FORWARD/REFLECTED POWER
meter's lower
scale should be zero watts.
(i) Set the
FORWARD/REFLECTED POWER
switch
to
FORWARD
.
(j) Continue to press the
OUTPUT POWER - RAISE
switch for a
DC SUPPLY VOLTAGE
meter
indication of the PA voltage recorded as PA
VDC - (Fwd Pwr Set to Assigned Level)
in
table 5-6.
(k) Forward power indication on the
FORWARD/
REFLECTED POWER
meter's upper scale shall
be the same as the Forward Power reading
recorded in table 5-6.
NOTE
Due to variation in the dummy load or antenna
system, it may be necessary to adjust the PA voltage
slightly to obtain the desired power level.
(l) If necessary, press the
OUTPUT POWER RAISE
or
LOWER
switches to set RF output power to
the desired operating level.
(m) Connect a digital multimeter between TP7 (+)
of the control/monitor PWB (A14) and ground
and, if necessary, adjust the exciter's output
power until the digital multimeter reading is
within ±0.2V of the voltage recorded as
RF
Drive Level (A14TP7) [___ Fwd Pwr] in table
5-6.
(n) The total current indication on the
DC SUPPLY
CURRENT
meter's upper scale should be within
±5 amperes of the
Total Current
reading
recorded in table 5-6.
(o) Set the
FORWARD/REFLECTED POWER
switch
to
REFLECTED
.
(p) The reflected power indication on the
FORWARD/REFLECTED POWER
meter's lower
scale should be zero watts.
4.10.5 PUTTING TRANSMITTER IN
SERVICE: The transmitter may now be connected
to the antenna system (if a dummy load was used)
and proof of performance tests may be done.