DeHavilland UltraVerve tube rolling

Thank you for checking.

It won't fit, unfortunately. I measured a vintage RCA 5U4G, and at that point the diameter is equal to or slightly greater than 1.75 inches.

Regards,
-- Al

Al,
The distance from the top of the preamp (where the tube hole is) to the upper surface of the tube socket is 2". The diameter of the hole is 1-5/8". Can you tell me what the diameter of the tube is at that point? Thanks.

That would be 5U4G. Based on the info at the deHavilland site, it appears that the 5U4G, 5U4GA, and 5U4GB would be suitable. The 5AW4 is also suitable for at least some versions of the Ultraverve.

According to my older GE and RCA tube manuals, the coke bottle-shaped 5U4G reaches its maximum diameter of 2-1/16" at a point 3-3/16" above the bottom of the base/top of the pins. The RCA manual indicates a tolerance of +/- 3/16" on the height of the tube, and presumably some of that tolerance would apply to the 3-3/16" figure. Hopefully that will be enough information for you to determine if that tube will fit. If not, if you can indicate how far below the panel the upper surface of the socket is, and the diameter of the opening, I can measure the diameter of a 5U4G I have at the corresponding height.

Regards,
-- Al

Cannot remember what 6AH4 or 5UG tubes my buddy uses in his but we went through a bunch of 6SN7 and the Tung-Sol round plate was the best of the bunch. Here is some of them we recently tried:

Ken-Rad black glass
Ken-Rad clear glass
CBS
RCA gray glass
RCA 5692 red base
Shuguang Black Treasure
Electro Harmonix Gold Pin
Sylvania green lettering
Raytheon
Macroni

Hope this helps.