General aviation pilot reported operating for a portion of time with no radio communication in the Gladden MOA due to the lack of good antenna coverage with ARTCC.

Narrative

I am filing this report as a general concern with FAA ARTCC radio communication coverage. Several times now enroute to 27AZ I have been unable to reach Albuquerque Center on 128.45 while above 7000 MSL in the Gladden 1 MOA.Other times I have been in contact with LA Center on 128.15 and when handed off to ABQ on 128.45 - nothing. I don't believe they have good antenna coverage in the Gladden 1 MOA area to the floor of the MOA (7000 - 17999 MSL) which creates a safety issue in that I am forced to operate for a portion of time in the Gladden MOA with no radio coverage by the controlling agency.I have also read a federal docket that Luke AFB proposes to lower the floor of their MOA from 7000 MSL (5000 AGL) to a much lower height. If they do; there will be no radio coverage for general aviation aircraft operating in this region. I should also mention this area is a common VFR corridor for transitioning general aviation aircraft.I have been in contact with Luke AFB representatives and requested a way to contact the Luke Range Control Officer via telephone or email to determine a safe time for me to operate in the Gladden MOA but they are unwilling to provide that information.