Rev A
FM250G User’s Manual
2—4
2.3
Frequency (Channel) Selection
You may select an operating frequency of 87 to 108 MHz in the FM broadcast band.
Pins 2 and 3 of JP1 on the RF Exciter board are jumpered for these frequencies.
To adjust the operating frequency, follow these steps:
1. Remove the top cover by removing 18 screws.
2. Locate the RF Exciter board and identify the frequency selector switches which
will be used to change the setting. See Illustration 2–3, Top Cover Removed,
and Illustration 2–4, RF Exciter Board (Frequency Selector Switches)..
3. Use small flat blade screwdriver or another suitable device to rotate the
switches to the desired setting. (The selected number will appear directly
above the white indicator dot on each switch.) See examples of selected fre-
quencies in the illustration below.
Illustration 2–3 Top Cover Removed
Illustration 2–4 RF Exciter Board (Frequency Selector Switches)
Illustration 2–5 Example Frequency Selections
fi
RF Exciter
Frequency
Selection Rotary
FM250
Modulation
Trim-pot
MEGAHERTZ
.1
.01
= 88.1 MHz
= 107.9 MHz
