[ADTech]

K42AC shares a Jampro JA/LS-8 with K38AI and K40DD up on Mingus Mtn and the antenna is H-POL only, none of them are licensed for any vertical component in their signal. Their antenna is, however, highly directional to the east-northeast with a good amount of electrical down tilt (3°). K42AC, however, maxes out at only 5 KW ERP along its maximum strength signal path compared to 12-15 KW for the other two stations on the antenna. The worst case, if one were situated in one of the weakest nulls, would be that only 920 watts might be sent in that direction. By contrast, K38AI peaks out at 15 kW with a minimum of 2.65 KW in its deepest null.

I suspect the much lower ERP and the directional antenna are the root cause for the difficulty in receiving K42AC as compared with its neighbors, depending o the relative direction and distance of the receiving location relative to Mingus Mtn. The weaker UHF signal of K42AC will be much less capable of diffracting to lower elevations where terrain is an issue or even for simple longer distance locations, even with LOS.

My interpretation, based on the antenna patterns and the City of License for each facility, is that KAET intends K42AC to cover the Cottonwood side of Mingus Mtn and for K43LW, located on Mt Francis, to cover the Prescott side.