RX antenna auto switch

Designed for use with IC-7300 and enable the use of a dedicated RX antenna.

Device connects to ACC 13 pin connector and taps on the "SEND" (pin 3), GND (pin 2), and "13.8V" (pin 8).

Toggle switch SW1 can be used to select two "modes": a) use primary antenna for RX and TX (one antenna mode) b) use primary antenna for TX and optional antenna for RX (two antenna mode).

Momentary switch SW2 is can be used when SW1 is in "b" mode (two antenna mode) to temporarily switch between two antennas on RX. No effect in TX.