As much as I hate to be that guy, I don't believe anyone will find a concrete answer as to what this thing is unless someone checks out the downed one. However, with imagery being a decade old just about it could very well be long gone.

My money's on a 2 crammed into some custom housing.

I have another Modulator for you, this time in Valkenburg, near Maastricht
50.86300238932366, 5.837202641677031

Edit: Also, one more in Cadier en Keer
50.83477138504861, 5.761022008784594

and in Mheer:
50.780641691932686, 5.792437069576436

and in Andel:
51.779433307538, 5.053366001390026

The only thing I can tell you is M98 is a date code, 98 of course being 1998, and the M standing for the month of October.

I would not be surprised if those were former Soviet S-28s and S-40s.

There was a Thunderbolt in Ottawa, ON?? https://www.google.com/maps/d/u/0/viewer?mid=1-CqL-LQK4beu5dcKcHvnUNyKXok3j0b8&hl=en_US Yeah, there was. I have an article buried deep in the pit known as newspapers from 1955 if I remember right that says Ottawa had a Thunderbolt on some building. I'll h...