When was used the last color studio camera equyped with electronic tubes?

Don't know without some research - but there is a second part to this - the early HDTV cameras were still tube pickups when NTSC and PAL cameras had already gone to CCDs. The CCDs at the time did not have enough pixels for HDTV.

I was talkin' about cameras with electronic tubes, like TK-41 :D

the last tube cameras were built until 1991,like the sony bvp-360 shown in the pics.. uses 3 plumbicon tubes..hitachi and ikegami all ended tube cameras at the same time..
i have 2 of these.!they work excellent.. and in one of the pics it is feeding a roundie ctc-7 if you can find it..
and i am holding $35,000 in my hand from one of sony bvp360's,an optical block assy with pickup tubes.. they are no way as large as what was out in the early days of color,this was sonys last tube broadcast Studio camera.at a price of $200.000 per camera .these cameras give a "film " like picture..
at a push of a button from the camera control unit the camera will then go thru auto setup..it will even do complete zone convergence.. corners and all all by itself,the lens has a built in test patten and regulated light built into..
kinda fun to watch this all happen.. and listen to the motors spinning around test patterns as it setsup all by itself

I was talkin' about cameras with electronic tubes, like TK-41 :D
I think there is confusion going on here between PICKUP TUBES and VACUUM TUBES.

If you mean cameras using vacuum tubes in the electronic circuitry, then the RCA TK-41C introduced in 1962 would be the last. That camera used vacuum tubes in all of its circuitry except for FET preamps in each Image Orthicon color channel.

The next step was RCA's TK-42, introduced in 1965. That camera used totally solid state circuitry for its 4.5" Image Orthicon (luminance channel) and three Vidicon pickup tubes. Most of the solid-state circuitry was contained in plug-in modules.

The TK-41s began entering retirement in the late sixties when Plumbicon cameras were introduced. All of the Plumbicon cameras used solid-state circuitry.