MM6SNT

Where's the amplifier? Looks a long reach to the rig, but might be illusion? Nice benchtop.

Well is circularly polarized so it can only really be for one thing. Can you say Sputnik ?

CPSARC new comp yagi.... fries everything in its path...

Good for interstellar comps as well.... 😂😂😂

So, it's not an antenna for a death ray? Powered by Italian watts... ?

Helical suggests something that’s likely to rotate and not be perfectly aligned on the far end. Satellite is the obvious one. It’s an end fire with reflector so probably relatively high frequency rather than using a coil as a shorter than quarter wavelength vertical. The one thing that makes me think not satellite is the support cables look like it only elevates to around 60 degrees max. So on that basis, possibly vhf to planes, particularly military jets as they wouldn’t always be flying level.

Eme or inter planet probes?

Pretty sure it's one of these. They were a very common antenna system in the 70's and 80's.