Protection
The BLA350 Plus features several protection circuits
that will protect the amplifier from damage. These
include: Excessive input power, Excessive transistor
temperature, Excessive output VSWR and incorrect
filter selection.
Should one of the above conditions occur the ampli-
fier will automatically disable operation, returning
the amplifier to Standby mode and will sound an au-
dible alarm at the same time as showing the error
message on the LCD display. The Warning (
e
) LED
will also be illuminated.
Excessive Input Power
If the input power from the transceiver is about 13W
the red warning LED (
e
) will illuminate and the
LCD display will return the following message.
If the input power increases above 15W the amplifier
will shutdown , an audible error tone will be emitted
and the Warning LED (
e
) will remain illuminated.
The LCD display will return the following message:
It will be necessary to reset the amplifier, this can be
done by switching the amplifier back to Standby and
then back to Operate using switch (
\
).
Over Temperature
The temperature at the point of contact between the
transistors and heat sink regulates the speed of the
cooling fans.
At between 65°C and 74°C fan speed is high. When
the temperature increases to 75°C the amplifier will
sound the over temperature alarm, The fan speed will
run at maximum, an audible tone will be emitted and
the warning LED (
e)
will be illuminated.
If the temperature increases above 80°C the ampli-
fier will shutdown, the audible warning will continue
and the alarm LED will remain illuminated. The am-
plifier will return to normal operation automatically
when the temperature drops below 60°C. It is recom-
mended that under this condition the BLA350 Plus is
not switched off, as the cooling fans will cool the am-
plifier down much faster.
Excessive VSWR
The BLA350 Plus measures both the forward and
reflected power at the antenna output and also at the
input to the low pass filters. The antenna VSWR pro-
tection features a lightning fast hardware protection
circuit. However both protection circuits are also
monitored by the microprocessor.
The amplifier will protect itself if the wrong band
filter is selected or if the antenna VSWR is exces-
sively high.
The amplifier operates at its best when the antenna
VSWR is below 1.5:1. If the antenna VSWR in-
creases from 1.5:1 to 2.0:1 the amplifier can still be
used however the reflected power will be dissipated
by the transistors which will cause more heat to be
generated.
If the antenna VSWR increases about 2.0 to 2.5:1 the
amplifier will protect itself by shutting down and re-
turning to Standby state. An error tone will be emit-
ted , the warning LED (
e
) will be illuminated and
the LCD Display will show the following error mes-
sage:
To reset the amplifier it is necessary to switch it OFF
and back ON again with MAIN ON / OFF switch
(
a
).
Filter Error
The Low Pass Filters are controlled and monitored by
the microprocessor in order to verify that the correct
filter is selected. If the user incorrectly selects a low
Pass Filter in manual mode the amplifier will signal a
warning and protect itself by shutting down and re-
turning to Standby state. An error tone will be emit-
ted , the warning LED (
e
) will be illuminated and
the LCD Display will show the following error mes-
sage:
To reset the amplifier it is necessary to switch it OFF
and back ON again with MAIN ON / OFF switch
(
a
).
Error Frequency
If the input frequency to the BLA350 Plus is outside
of the specified limits the amplifier will shutdown,
the amplifier will be returned to Standby condition,
an audible alarm will sound, the warning LED (
e
)
will illuminate and the LCD display will show the
following error message:
P o w e r T R X
>
1 3
W
T
: 2 8
° C B
: 2 0
-
3 0
m
E r r o r P o w e r T R X
T
: 2 8
° C
O V E R T E M P
!
T
: 8 3
° C
E r r o r S W R
>
3 . 0
T
: 2 8
° C
H a r m
.
S W R
>
3 . 0
T
: 2 8
° C
E r r o r
F r e q u e n c y
T
: 2 8
° C
3 0 . 2
M H z
9
Содержание BLA350 PLUS
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