Can the 6S33S/6C33C be mounted horizontally?

[ben_f_m]

Has anyone thought about mounting the 6S33S horizontally? I have some rack mount air force power supply chassis in which all of the tubes were mounted horizontally in a center cavity open on the top and the bottom. It seems such an arrangement could help keep the temperature down as heat is a common problem with these tubes.

 

[kevinkr]

The data sheets I believe mention vertical operation only, and the filament/cathode assemblies in 6C33 run so hot that I suspect sagging and shorting to the grid is a real possibility. (The grid structure may also sag) Forced air cooling isn't going to reduce the cathode temperature at all, although with these it is not a bad idea under any circumstance provided the fan(s) used are quiet enough not to be distracting.

 

[Wavebourn]

I have not seen specific requirements for mounting position, but if it must be alive after a single impact of 500g acceleration, or constant 6g of 10-300 Hz vibration, do you think a mounting position matters at all?

 

[mace1337]

I think they are mounted horizontally in the radar system they were originally designed for, I'll see if I can dig up the picture.

edit: here it is:

 

[kevinkr]

I've seen one of those at the MIT flea (hamfest) and asked the guy who owned it about the tube mounting arrangement, he indicated that they apparently needed fairly frequent service and ran very hot. I was amazed at how much stuff they packed into that box, and how nicely put together it was.

Regardless of military usage practices I think mounting these vertically is probably the safest bet despite their ability to survive short term high amplitude shocks. I'm not that sure about their long term mechanical integrity operated in any other position based on my admittedly limited experience with them.

The surplus tubes available today seem to come in several grades and I have had a significant number that were defective new out of the box. (Yes, with grid to cathode shorts due to a warped grid assembly - how it got that way I have no idea.)

 

[Jeb-D.]

They were used in Mig jets, so I highly doubt mounting position matters. The only thing I will point out is that the tube is heavy and the sockets don't grab really tight. You will need some kind of bracing to prevent the tubes from falling out of the socket.

 

[Wavebourn]

Regardless of military usage practices I think mounting these vertically is probably the safest bet despite their ability to survive short term high amplitude shocks. I'm not that sure about their long term mechanical integrity operated in any other position based on my admittedly limited experience with them.

Up to 35g during the whole guaranteed lifetime.

 

[FullRangeMan]

Deleted, irrelevant.