An interesting auction of unusual early tubes took place on eBay on Tuesday evening. The seller apparently didn't check common references, and may have been pleasantly surprised by what he had. This picture is rearranged, annotated and re-scaled to fit here, with the full link to the originals given below:
$423 eBay GE experimental tubes_160110.jpg [ 122.98 KiB | Viewed 283 times ]
The conical-anode tubes are discussed in Gerald Tyne's Saga of the Vacuum Tube
on page 153. The other tube appears to be a VT-11, as it has a Shaw base with what looks like a red wax fill, whereas I believe, CG-890s have ceramic inserts. The conical-anode tubes have their bayonet indexing pins at 45 degrees from the usual location, likely to prevent installation in a standard (navy-type, ~ well, pre-UV) receiver socket. Given the index location, I'll speculate these tubes may have been intended for transmitter applications.
To see the bases up-close, please go to the eBay link below, as I couldn't fit that picture into the above montage. (Next time I'll use multiple pictures, sorry.)
Bidding was rather amazing, and someone sure wanted those pretty things, price be damned. I had to drop out early, knowing $423 + shipping, etc. will do my family a lot more good than those wonderful rarities could ever amuse me. However, those cone-hats are really
neat to behold.
Comments and corrections would be appreciated.