NORMARC 7050, Руководство пользователя

Страница: 27 / 28

©1999 Navia Aviation AS 21464-5 Tests and adjustments
TRANSMITTER NORMARC 7050
MARKER BEACON
2-15
The RF
LEVEL
(output power) is adjusted by dragging the RF
LEVEL
knob. The value in volts in
the window to the right shows the control voltage to the power amplifier. If you want a power
indication in Watts, open the maintenance window and watch the CarrierPower parameter for
the selected TX1373.
Figure 2-7 Adjusting the modulation depth
Similar to above, the M
ODULATION DEPTH
is adjusted by dragging the M
ODULATION
knob. The
value is given in percent. This percentage is not the same as the modulation depth in the mon-
itor, but the percent of the RF Level DAC that is used to feed the modulation circuitry in the
transmitter.
Figure 2-8 Setting keying type
There are three possible keying alternatives: N
ORMAL
, C
ONTINUOS
and O
FF
, the two latter
used for test or maintenance purposes.
FAN MARKER
If the station is configured as a F
AN
M
ARKER
, the keying may be set quite freely. Each of the
24 Data boxes corresponds to one tick which endures for approximately 150ms. An X indi-
cates sound while an empty box indicates silence. L
ETTER LENGTH
is how many ticks are used
in a sequence. The table below shows the expected lengths for keying elements:
Table 2-3 Fan Marker keying elements
Let's say you want to transmit an X . Then you should program
DASH
-
SPACE
-
DOT
-
SPACE
-
DOT
-
SPACE
-
DASH
-
LETTER SPACE
. This gives a
LETTER LENGTH
of 3+1+1+1+1+1+3+2= 13 as shown
in Figure 2-9
Keying element #ticks
Dot 1
Dash 3
Space 1
Letter space 2