RE: dx7 + ar7000 lock out?
Way back when the DX6 came out I quickly bought one for my T-Rex heli. At work (Internet access provider) we have a tower in our parking lot that has 3 FHSS 2.4ghz wireless radios and some other 5.xghz stuff. I set up my Trex with the Dx6 at home and had flown it quite a few times with no issues whatsoever. I took it to work one day and couldn't believe the problems I started having. I could turn on the radio and everything initially would work, but then I started getting locked out and glitches. I could turn everything back off and then back on and it would work again. Turn it off and back on and it may start glitching again. Took the Trex and radio back home and not a single problem. Brought it back later than evening and the lock ups and glitches started happening again.
I figured out that when I turned on my Trex and Radio they were doing their thing and picking clear frequencies to use BUT a few seconds later one or more of my frequency hopping wireless radios up on the tower were hopping onto the same channel as my Dx6 radio...hence causing the glitch/lock up.
Same for you. The crew installing the antenna may have turned on a new radio system AFTER you had turned on your DX7. By chance, they were using the same frequency that your Dx7 had initially thought was clear. Once this happens your are destined to have interference. The FCC states that all license-free 2.4ghz stuff may not cause harmful interference, and also must accept any interference received, including interference that may cause undesired operation.
Just my thoughts