Id be interested in anybodies comments on those antennas.
What are the driven elements?
Its tough to see the jumper feedlines.
I can't see well enough to tell what is what. I noticed on these antenna a lot of the feed wires and matching sections are hidden so you can't even tell sometimes if a cover is cosmetic or a real "radome" to protect it from weather.
One some of the elements on these antennas you can tell their are passive easier than tell which ones might be active per what I said above.
I would be guessing on a lot of them and there are a lot of them. If I had multiple views it would help on some.
Good example. EV-ANT-108. The pull out UHF section is probably passive, but it might not be. I feel pretty sure the rear folded dipole element has to be active, probably.... How they match UHF energy is covered with plastic and could even be an element totally hidden.
It looks like the Nitro 3000's active elements are the longer aluminum tubes on the top and bottom on the frontside with a bunch of smaller directors in front of it........and the large VHF (High) dipole towards the rear. And it has a rounded corner reflector with a focus at where (on VHF frequencies? and on UHF frequencies?)
Is this a stacked UHF antenna combined with a VHF dipole all in front of a parabolic corner reflector?
This looks like a classic wideband design with lots of cute red rubber tips to give the impression such as racing strips do to a car.
I think you about pegged it, but again, guessing from a blurry blown up picture.
The directors do seem to be DC ground cut to the upper channel they wished for the antenna to cover.
I think but not sure, the upper and lower longer elements are the UHF feed elements in parallel, tuned to the middle or a little lower in the band. I think I can see wires from each one. The reflector appears to be circular from the angle I see in the picture with the classic lowest desired frequency to receive if this antenna were only UHF, but it's not.
The image is blocked but it looks like the folded dipole is continuous on top and broken on the bottom with feed wires. This would make sense anyway. It's really hard to tell. It probably has a little VHF gain from the reflector but not much or I would be surprised if it's much.
If it's stacked it's stacked really close. It follows more of the idea behind the XG91. More of a variation on the X-Directors like the Blake or the XG91.
Typical stacking distance for 600 Mhz for vertical stacking is about 20 inches (normally horizontal also, though the Blake is suggested at 44 inches probably more for multipath than gain).