User Guide

08905105A - 2 -
IR CARRIER ADJUSTMENT
The 490-85 is factory set to an IR carrier repeat frequency of 39kHz. This will be correct for the
majority of installations. However, some manufacturer’s components that you wish to control may use
different carrier frequencies (such as RCA DSS satellite receivers that use 56kHz). If sure carrier
frequencies fall within the range of 32kHz to 56kHz, you can adjust the 490-85 to match them for the
best range performance. The adjustment can be made through the small opening on the rear.
To adjust, proceed as follows:
1. First, try the 490-85 in a repeater system. If it works well with good range, do not make any
adjustments!
2. If it does not work or has poor range (less than 15 feet), determine the IR carrier frequency of
the product you wish to control. Contact the manufacturer of the product, if necessary, to
determine this frequency.
3. Using a small blade type screwdriver, rotate the adjustment shaft until the slot lines up with the
desired frequency.
4. If you have products in the same IR system that have different IR carrier frequencies, you will
have to adjust the 490-85 to a midway position. For example, some may operate at 38kHz and
others at 56kHz. In this case, set the adjustment to approximately 47kHz, a midway position.
Note: Some products are more tolerant of compromised frequency settings that others. You may
have to “fine tune” the adjustment to “favor” the least tolerant component for the best performance
of all units in the system.
Clock-wise (CW) Increase carrier frequency
Counter Clock-wise (CCW) Decrease carrier frequency
490-85 CABLE CONNECTIONS
The 490-85 may also be used where the 7-foot lead is not long enough. In this case, simply cut off
the mini plug, strip the leads and connect them to a 3-terminal block. For correct color identification of
wires, refer to the following tables and diagrams:
PLUG CABLE LEADS DESCRIPTION
RING BLACK GROUND
TIP WHITE IR OUTPUT
SLEEVE RED +12V
Tip
Ring
Sleeve
Insulators
Mini Plug
(3-Conductor)
3-Terminal
Block
OUT
+12V
GND
WHITE
3-Conductor
Wire to
Controlled
Equipment
490-85
7-Foot 3-Conductor Cable
with Mini Plug removed
See Tables for
Wire Color