Sub minature tubes..

[N2DTS]

I have a bunch of very small tubes, all 6.3 volts.

5899, semi remote pentode,
5718 medium mu triode
5840 semi remote cutoff pentode,
5840 sharp cutoff pentode,
6111 medium mu twin triode.

Something needs to be done with these little things, they are too cool to waste.

I suppose I could build some sort of audio circuit with the triodes, a mic amp or something.
These tubes do not have pins, they have wires coming out the bottom....

I wonder what sort of CW rig you could make with a bunch of these tubes...

[Opcom]

If you 're-use' circuit paths, you have more than enough for a small portable. It might be that those tubes fit some military sets and would be in demand, worth trading for larger quantity of conventional tubes of similar function.

[WD5JKO]

Brett, the story that follows is interesting.

The folks at Shiit audio came up with the Vali, a headphone amplifier that has a sub miniature triode connected pentode (6088) as the gain stage for each channel.

The story, starts at Chapter 31 about 1/3 down at this link:
http://www.head-fi.org/t/701900/schiit-happened-the-story-of-the-worlds-most-improbable-start-up/2700

Here is the finished product for sale:
http://schiit.com/products/vali

These might be good headphone amplifiers for the shack...

Jim
Wd5JKO

[KO6YB]

Hello N2DTS, the first three tube types you listed are used in the RCA built AN/SRR-11, 12 and 13 receivers. Definitely boat anchor receivers by weight, even with the miniature tubes.

They use 5 each 5899, 2 each 5840
SRR-11 VLF receiver: 5718 4 each
SRR-12 MF receiver:  5718 6 each
SRR-13 HF receiver:  5718 6 each,
Later SSR-13 S/Ns and SSR-13A use 1 less 5840 and one more 5718

Stan.

[N2DTS]

Neat stuff!
The 5718 looks like fun, 150 volts on the plate, 13 ma.
Or the 6111, 100 volts and 8.2 ma, maybe a push pull rig with both plates in one tube!
Modulate it with a pair of 5718's.
1.6 watts input to a push pull 6111 (both triodes).