There was an irregularly but often transmitting radio antenna tower fifty feet from my home, and the outage duration when an outage occurred was precisely the same each time, because Docsis is very carefully specified in how it starts up. (Don’t remember the duration, sorry.) The outage interval varied based on antenna usage; if OP is suffering a similar circuit break, a continuous transmitter nearby could certainly cause continuous outages at the regular interval “renegotiating, success, assigned channel collision” loop.
The outages mostly happened at very specific times during the hour (:29 and :44) for 17 months. It just doesn't add up to being RF interference, especially from a radio tower. But if OP has a radio tower 50 feet from their home, I guess we could consider it.
How did you know when the radio tower was transmitting?
The value here is “triage experiment: try an older modem”. If it reveals something, now they’re not stuck. If it fails in the same way, no knowledge is gained.
According to the article (again), he was using his own Xfinity-approved modem. I doubt his neighbor was also using the same model.
There's no point in performing random experiments if you've already ruled out those causes in some way. It would also require either renting a modem temporarily or buying one.
If that's a ham antenna, go talk to the guy and he might know some tricks for either shielding your connection (doubt that's possible though), pressuring Comcast, or else at least making an effort to avoid frequencies that interfere with your internet.
