Hi, Recently, I picked up an RCA AVA-68 Antenna Switch It is apparently used with the AN/APN-1 Radio Altimeter on the Canadian Lancaster, but this is the first I've ever heard of it. The unit is DPDT coax switch with SO-239 cnnectors, operated by a rotary solenoid mechanism. The reference is: http://jproc.ca/rrp/rrp3/lanc_equipment_details.html