John W Moreland and his Galena diode.

[telecom]

I was thinking about a diode, not a triode, something along the line of a Geiger counter - the same idea.
But Galena is a good start as well.
Regards

[pomodoro]

It seems that a very knowledgeable person on here has already made these using thorium. Going back a few years, here is the link , reply #8. He managed to power a speaker directly without an impedance transformer.
http://overunity.com/6970/stubblefiled-meucci/msg162514/#msg162514

[telecom]

Yes, this looks as a step in the right direction.
Not sure exactly how it works, perhaps the
radio frequency gets into the resonance with the
helium atoms which causes increase in alpha decay.

[pomodoro]

So, if these uranium doped diodes work, even just a little, they apparently require signals that have some form non uniformity to trigger the amplification. Thus AM radio signals and music or voice should do the trick.  I plan to use one as a crystal detector as I mentioned. I'm guessing that the crystal would work as a negative resistance. The aforementioned link describes the doped crystal as increasing the current but not the voltage. The generated current in the crystal would need to flow through the tuning coil to complete the circuit.  Its not a double ported system like a transistor amplifier.
However, Moray is said to have powered an RCA horn speaker with a similar crystal. These loudspeakers had an impedance of about 2000 ohms and require a reasonable voltage to work. One watt would require about 44V rms.  I can only guess he must have used a matching transformer with the speaker.

Im thinking that a simple crystal receiver with an adjustable load should be enough to tell if there is anything special going on. The doped crystal should be able to keep the voltage on the load higher as I decrease its resistance.  Of course a speaker is another less scientific test.

For audio testing, A small simple audio amp will be built to test the 2N2222A with the uranium oxide packaged inside its casing.
Any comments, criticisms or ideas,  are welcome.

[profitis]

Heating lead powder/filings plus sulfur powder/UO2 in a ceramic tube should do the trick for fusing ala the classical old-school iron filings/sulfur mass reaction.I recomend trying lead/selenium..lead/tellurium mixes too for similar bandgap chalcogenide semiconductors from the sulfur family