Kt88 vs 6550

[Mars Amp Repair]

Hello folks,
I was just contemplating my naval, and wondered if 6550 tubes that replace the KT88's are also of the 'Kinkless' design. I imagine to be a sub, they probably are, but don't really know?!
File this under weird things we techs think about in idle times...good reason to stay busy!!!!

[Helmholtz]

Hello folks,
I was just contemplating my naval,..

What does this mean? Did you mean navel? Foreigner here.

..and wondered if 6550 tubes that replace the KT88's are also of the 'Kinkless' design.

Both the 6550 and the KT88 are beam power tetrodes, so I'd think yes.

[g1]

What does this mean? Did you mean navel? Foreigner here.

Yes, it is an english language slang expression.
https://en.wikipedia.org/wiki/Navel_gazing

[Helmholtz]

Yes, it is an english language slang expression.
https://en.wikipedia.org/wiki/Navel_gazing

Thanks. I just wondered what battleship he was looking at .

[pdf64]

My understanding is that 'kinkless tetrode' is purely a marketing term.

[Mars Amp Repair]

HMM,
I kinda understood that the original arrangement of grids in the tube created a 'kink' in its response, so they arranged the grids so that they didn't interfere with each other remedying the 'kink' issue, but I see numerous articles that indicate pretty much what Hemholtz has stated. The development of the Beam Power tube remedied the 'Kink' in the plate response.
Man...now I have to find something else to contemplate during those idle times

[Helmholtz]

Plain tetrodes show a distinct kink in the lower plate curves. The kink means a region of negative impedance which can cause instability.
The kink could be (almost) eliminated by adding another grid (-> pentode).
To circumvent the Philips of the Netherlands pentode patent, competitors (EMI/UK) developed an alternative by adding beam confining plates to the tetrode (-> beam tetrode).
So pentodes as well as beam tetrodes are essentially "kinkless".