As usual ,what type of antenna. Didnt CBC and Global switch over to digital in Barrie? . If so to which channels? Ch 20 CBC is acctually CBLT from CN Tower , I guess they use a different frecuency in Barrie. Same for Global, although they could have flash cut and used the same channel than before when it was analog.
Are all trnsmitters located in the same tower if not , how wide apart (which directions to aim). You can also email the local tv station engineer and they will likely tell you what to do.