Front Panel Controls and Indicators, continued 3
F6 – OFFSET Switches
The OUTPUT CHANNEL switches set the output
frequency for a visual carrier frequency of ‘xx.25’ or
‘xxx.25’ MHz only. The exact output signal frequency,
however, is relative to the input signal frequency and any
additional offset (plus or minus) set by the OFFSET
switches. For example, an input signal of
229.2625 MHz (+12.5 kHz offset) and an OFFSET switch
setting of ‘0’ would result in an output frequency of
‘xx.2625’ or ‘xxx.2625 MHz.
Input Channel
Output Channel
Offset Switch Settings
Off Air channel 25
Standard CATV channel 44
+2 x 6.25 kHz = +12.5 kHz
(537.25 MHz)
(343.2625 MHz, includes
(Output frequency = 343.2625 MHz)
+12.5 kHz aviation offset).
Standard CATV channel 25
Standard CATV channel 44
0 x 6.25 kHz = 0 kHz
(229.2625 MHz, includes
(343.2625 MHz, includes
(Output frequency = 343.2625 MHz)
+12.5 kHz aviation offset).
+12.5 kHz aviation offset).
Standard CATV channel 25
Standard CATV channel 78
-2 x 6.25 kHz = -12.5 kHz
(229.2625 MHz, includes
(547.25 MHz, no offset
(Output frequency = 547.25 MHz)
+12.5 kHz aviation offset).
required).
In a similar fashion, output OFFSET switch settings plus
or minus in various 6.25 kHz increments will modify the
exact output frequency accordingly. Multiply the
thumbwheel switch number times 6.25 kHz to determine
the offset. For example, a setting of ‘”2” sets a 2 x
6.25 kHz = 12.5 kHz offset. Remember to also set the
direction of any offset plus or minus as required. Certain
CATV channels require aviation or navigation offsets.
Several examples follow:
F7 – OUTPUT CHANNEL Number Switch
Sets the output channel number for standard CATV
channels 02 through 78 and 95 through 99. Note that
these switches set the output frequency for a visual carrier
frequency of ‘xx.25’ or ‘xxx.25’ MHz only. Any required
offset must be set by the ‘OFFSET’ switches with
knowledge of the input signal frequency and required
output frequency. See Table 2 in the ‘Installation’ section
of this manual for a list of output channels and any
required aviation offsets.
F8 – OUTPUT ENABLED Indicator
Lights to indicate that a valid channel is selected and an
input signal is being received. The RF output is switched
off for any invalid output channel settings, no received
input signal as set by the input channel switches
(‘SIGNAL’ indicator is off), or other conditions that would
cause the unit to operate on an invalid frequency. See
also Item F4.
F9 – RF OUTPUT LEVEL Control
This screwdriver adjustment varies the RF OUTPUT level.
Clockwise rotation increases the level.
OUTPUT
CHANNEL
x 6.25 kHz
RF OUTPUT
OFFSET
4
4
2
--
+
OUTPUT
CHANNEL
x 6.25 kHz
RF OUTPUT
OFFSET
4
4
0
--
+
OUTPUT
CHANNEL
x 6.25 kHz
RF OUTPUT
OFFSET
7
8
2
--
+
