Priority Channel Board

The CHIPSWITCH chip comes with the capability to program a particular frequency as a priority channel. However, for this feature to work properly, additional circuitry needs to be added to allow the squelch circuit to respond faster to changes in signal strength. This is needed because when the priority channel is activated, the radio tries to go out and periodically check the priority frequency for activity. Since this must be done very quickly (<100 ms), the squelch time-constant capacitor's function must be changed. The PRIORITY CHANNEL BOARD allows the squelch input to the CPU chip to respond instantly to changes in signal strength, yet keeps the radio's audio MUTE and AGC circuits working normally. The PRIORITY CHANNEL BOARD is a small circuit board (1.9 by 1.1 inches), and takes about 1 hour to install. It comes with complete instructions. It can be purchased separately and installed anytime. (It does not need to be installed at the same time as the CHIPSWITCH IC unless you wish to have priority channel function immediately.