10
AP Series
Instruction Manual
Option 12 - Automatic Broadcast Offset Correction (ABOC)
With the use of Option 12, all input offsets are fully corrected to allow precise control of output offsets. This allows
for control of FCC 21005 Offset requirements completely independent of the input offset. Using Option 12, there is no
need to measure or determine the input offset frequency whether it is broadcast or from a cable channel. All inputs up
to ±25 KHz offset are fully corrected. Once selected, the output channel will maintain that offset even if the input offset
varies. A green Front Panel Indicator shows that the ABOC is on and the input offset has been fully corrected.
Option 12, ABOC should be turned on when using an AP as a converter in the “Off-Channel” mode where the ouput
channel differs from the input channel. The input channel is selected by means of Front Panel DIP switches
corresponding to the input channel. The output channel is selected by Front Panel DIP switches and set according to the
output channel. ABOC On/Off position controls ABOC operation. With the 4th switch UP the ABOC is activated and the
output offset frequency will be maintained independent of the input offset. It is recommended that the ABOC be kept
on during “Off-Channel” operation, thus keeping the output offsets controlled.
During “On-Channel” operation, the ABOC should be switched off. In this mode, the output frequency will remain
exactly the same as the input frequency.
During “Off-Channel” operation with the ABOC off, the output offset will no longer be accurate but will be a
function of the input offset which may be unknown.
CHANNEL
EAS
LEVEL
AURAL
1
2
4
0 - 9
00 - 12
8
4
3
2
1
1
2
4
8
OFF
ON
OFFSET
SUM UP SW
CATV
3
2
1
3
2
1
STD -
U
D
0
U U U
IRC - U D U
HRC -
BROADCAST -
U U D
U D D
Operating
Mode
Input Channel
Selector
Options
Selector
UP - ABOC = On
DOWN - ABOC = Off
Offset Selector
Switch UP = ABOC ON
Switch DOWN = Variable Offset
Notes:
1. When ABOC is “ON”, the offset switch must be set to “OFF” (UP) position.
2. For “On Channel” operation: ABOC is “OFF” and offset switch is UP.
3. For “Off-Channel” operation: with ABOC off, output offset will not be controlled by the
processor but by the input frequency. Offset switch is down, variable offset may be adjust-
ed at the front panel.
