Nice to see some of television's history. Also great to see how 'Lo-fi' they are.
I always thought how dull the TV communicators seemed compared to the all metal replica pins, popular at the time. But I suppose it makes sense, you wouldn't want a potential glare item on everyone's jacket on set!
Treasure them, I'm surprised no one has commented on these since February!
I have a production-made TNG comm badge somewhere. It's very similar to yours, except the back is dug out in a square about 1/2" x 1/2" X 1/8" deep, with the velcro hot-glued into the cavity (though it fell out many years ago). I got it after my set visit during the filming of Sins of the Father in Jan. 1990. But apart from the shape of the velcro cutout, and the condition of the paint (mine's lost its sheen but is intact), I'd say yours looks very consistent with mine.
Since these things are so easily copied, though, your provenance is more important than a match to another piece. If you got it from someone on the crew (as I did), I'd say you're probably solid.
Is there in fact an actual difference from the the early episodes to the later ones? I've always felt just from watching the show that they looked a touch different but have never seen a side by side comparison of two different styled TNG comms.
They look legit. I have a later TNG style comm badge, and the gold oval looks a little different than your early season version. It's possible that around season 3 when they switched uniforms and some production design that they retooled the comm badges. Your Voyager badge is dead on to my original as well. It seems most of these were made with a flat black dye to the resin, and of course with an indent for the velcro. Not all replicas copy those details.