You may see references to a "PL" board. is Motorola's trademark for CTCSS (Continuous Tone-Coded Squelch System). The base SP10 does not include this feature, but an optional accessory board can be installed internally.

: Indicates when the radio is transmitting (red) or receiving signals. Repeater Builder® Setup and Basic Operation Installing the Battery

: If your SP10 has an optional PL board, you will find a second bank of 8 DIP switches. These switches are used to set the radio's CTCSS (Continuous Tone-Coded Squelch System) code, which filters out unwanted transmissions. Each 8-switch combination corresponds to a specific tone frequency (e.g., 67.0 Hz, 71.9 Hz, etc.). For accurate tone programming, refer to the official Motorola SP10 service manual or an online CTCSS tone chart.

Solid Green: The radio is receiving a signal (or squelch is open).

Continue rotating the same knob clockwise to increase the volume or counter-clockwise to decrease it.

You’ll find two primary knobs. The one on the far right is your Power/Volume dial. Give it a click clockwise to wake the beast. The smaller knob next to it is your Channel Selector , usually offering 1, 2, or 10 channels depending on your specific model.