Am I correct in presuming that since 46.220 is in carrier squelch when simulcasting TG 1680 that it's a one-way only link (800 TRS to VHF low band)? I'm gathering that it's set up for members with 2 channel pagers who, once paged on 46.260, can switch over and monitor ops while enroute to the firehouse.
Scan, yes that is the reason. Yorktown Heights FD had switched their responses to Fire 17, but when they found this "problem" they reverted back to 46.26MHz. And actually it is 470/476MHz to low band not 800MHz.