Unless things have changed basic Northstar dispatch is simulcast on both the 155.295 frequency and the 26832 tg. One scanner in my listening post is always monitoring the Northstar/Southstar tgs exclusively and I've heard the Northstar dispatch come over both the tg and the VHF frequency simultaneously. The reason for the fly, and all the flight/lz details come over only on the tg, but the initial basic dispatch is simulcast.
Another tip if you enjoy monitoring EMS is to program the various EMS/Trauma tg's in your scanner. Often times you will hear inter-facility transfers being set up or 'heads up' calls being given to hospitals that one of the medi-vacs will be enroute to their facility. I've also heard 'heads up' calls being given from ALS units in the field via their dispatch that a medi-vac may be, or is, needed. The ALS dispatch agency will then contact the appropriate medi-vac dispatch.
Have fun monitoring!