This is just an odd quick little post for curious experimenters...
it doesn't prove much of anything.. just a little quick test for fun.

Maybe if you're curious like me... and always learning like me.. you'll appreciate it.

So... Like the title says.. I was just experimenting and piddling around with some nice new 5902 peanut tubes I just received.

These tubes are earmarked for a new little PP audio amp for an Ipod (or other Mp3 device) that I'm about to build as a lark.... soon as all the parts arrive..

A generous ARF member gifted these to me for the price of shipping ( thanks again)

Anyway I was anxious to see how these little things worked.

I read that the 5902 is almost the same as a 6v6 except for lower plate voltage.

I just finished up my Silvertone-1962 PP radio here that uses 6F6s in push-pull.

Since it was sitting right on my bench anyway ....I thought I'd try a quickie test in circuit!

( I like to play Edison)

So first I just swapped the 6F6s for 6v6s to see how they sounded... and they were fine..okay.

Then I pulled out one of 6v6s and tack soldered the filament of this 5902 in place.

Then, for safety, I sleeved the leads with heat-shrink tubing and then started my experiment.

I first pulled off the normal 228 volt B+ cathode lead off the 5W4 rectifier, and then I inserted two 1k 5watt resistors in series to drop the B+ down to something the 5902 can live with (150volts or so)
And so... now my adjusted B+ drops to 130 under load.

Then I just started clipping in jumpers from the 5902 leads to equivalent pins on the empty 6v6 socket.

I fired it up and measured plate and screen P= 120v S=130v

Nice.

I have a 300 ohm cathode resistor already in there ... and that measures 10volts on it.. limiting plate current to 30ma

Right at the recommended point.

So.. since everything seemed fine... and the radio was working... I just cranked up the volume.. and to my non-audiophile un-trained ears... it sounds perfect.. same as with two normal 6v6s...

Ok.. experiment over..
5902 tube works fine...
Clean up the rat's nest now.

Did you have fun?

Sure Peter, always fun to play around with the hobby. I have done a few things like that myself. I took an old beat up Hallicrafters S-38C. Used a 12 volt transformer to run the 3 12 volt tube heaters, a diode for a rectifier, used then an old computer speakers PC board for an audio output, with both channels coupled together for a mono output. Used the same 12 volt transformer with a full wave little bridge an filters to power that. Added a tone control where the stand by switch used to be. An FET transistor and circuit for a wide band antenna amp from that power supply too. Worked pretty good, I gave that one away. Here is a link where if you want to play around some. Try some of this. I have made a few Hot Rods out of some common AA5. Have fun.

http://www.geocities.com/wa2ise/