Mysterious vacuum tube

[Xeno Xenox]

A friend found this vacuum tube on the beach near San Francisco.

Can anyone help me ID it? Anything would help -- function, age, manufacturer, etc.

I haven't seen it in person yet, so I can't say whether it has any legible markings.

 

[Bluejets]

4 pins....rectifier?

 

[Xeno Xenox]

I think we figured it out. It appears to be an RCA Radiotron UX-171-A, used in the final stage of radios and televisions for audio amplification.

http://www.nmr.mgh.harvard.edu/~reese/RC10/RC10-76.GIF

 

[dorke]

It has 4 pins, 2 thicker (any side bayonet pin ?).
Better quality pictures from all sides may help.

The socket is called UX4( U4A).

 

[Externet]

Read under the base; ----> http://www.geocities.jp/radiomann/HomePageVT/Radio_tube_13A.html

 

[JRUBIN]

4 pin, directly heated cathode no doubt. Triode amplifier, pins look a bit worse for wear. I bet it still works if it hasn't been breached.