'Separate antennas', meaning APRS digi and repeater antennas. I figure the APRS digi was used with it's own antenna so it's available. Right? Keeping both systems separate makes for a simpler way of making changes to either system. One won't affect the other. It's basically a 'what's available' kind of thingy.
Quote from my original post "Our club repeater has been configured for separate rx and tx sites" Yes, we have 2 vhf antennas, one at the rx and one at the tx site at which I used the duplexers to combine the repeater transmitter and APRS rx/tx radio. Each site also has a UHF linking antenna.