danikayser84 said:w9wi: Does it matter if the signal is directional or not, like with AM? When a 105.7 (now WQSH) moved from Glens Falls to Albany, it had to change from nondirectional to directional to protect a 105.5 (WSKU) and 105.7 (WMRV-FM) to the west and a 105.5 (WVEI-FM) to the east![]()
As Scott says, you can't use a directional antenna to allow *allocation* of a channel to a city where it couldn't otherwise be allocated. You can use one to allow installation of the *tower* in a location where it wouldn't otherwise be permitted. But there's a limit to how much you can reduce protection distances by using a directional antenna, and the distance figures I posted already take that into account. (so you can't use a DA to locate a hypothetical 94.9 station closer than 60 miles to WZZO, for example.)
I think the bottom line is, as Scott says, with so much money at stake, if it was possible to use a frequency in Philadelphia, someone would have already done it.