Hi All, I have a question for some RF guys.

I'm in a fringe area for UHF reception off sugarloaf (no LOS to sugarload directly but only 10km away from the tower) I can pickup TVNZ channels fine, but Mediaworks channels (32) I get very low if no signal at all. (Same for Aljazeera) 

My aerial is a UHF only aerial (in a very difficult position to replace, would need scaffolding, but is relatively new) with a masterhead amplifier. 

I'm keen to know if anyone has any ideas on how i would get a OK, and watchable signal for the TVNZ mux but not others, seems strange as the frequencys are very close, unless the Mediaworks MUX is slightly lower power?