Since 06/04, overnight tropo has been pretty decent most nights. I logged the AirLink helo on their VHF channel on 06/04, 06/10 and this morning. I have not heard their flight watch base.
Some of what I have heard is simply interfacility transports, such as to / from UNC Hospitals.
I was hearing them around 2130-220 hrs last night, and heard their base acknowledge. The antenna for the base is on the same tower as the primary NHC trunking site, and the vhf antennas are not very high.
If I'm not mistaken the VHF base for AirLink Ops is a Motorola Quantar. At least that's what it was when I installed it....