FDIM 2022, 2N2222A Power Challenge Winner!

My design for the FDIM 2022 power challenge: to produce as much power as possible, sustained for 1 minute continuously, with a crystal controlled oscillator / power amplifier using just TWO 2N2222A transistors as the only active devices! At 4.1W, the result was more than double the record from previous years.

[@ralphmills7322]

I see that having the "Dollar Tree" plate engraved would have broken the FDIM awards budget. Thank goodness someone remembered to bring a "Sharpie" marker or Hans effort would have gone unrecognized. 😀
I am reminded of an old joke about a man who was tarred, feathered and threw out of town on a rail. When asked how he felt about it he replied "If it wasn't for the honor of the proceedings, I've just as soon have walked!"

[@Randrew]

That is completely awesome, Hans! I do especially love your heatsink innovation! In hindsight that I would not have anticipated until I saw the drinks in the video, you could double the duty of your device as a "tea maker" by immersing the tubes in cold (distilled) water and running the supply voltage up, up, up!

[@johnwest7993]

Ingenious, especially the xtal coupling. Well done.

[@joeteejoetee]

Yes indeed!

[@wmb2292]

I love to see what happens when people think outside of the box ... absolutely brilliant ! - de VE3WMB

[@deBug67]

Great work 🙂👍
Looked like you had a lot of fun with a great crowd.

[@R2AUK]

👍❤

[@adamrong8990]

Wow! Smart design and excellent result. Congratulations, Hans!

[@N2AIE]

nice to see David NM0S there helping

[@mikestokes235]

Well done Hans!

[@GarethHowell]

What great fun, Hans.

[@Derrick6162]

What great fun that would have been. I would like to do something similar one day. Could that be referred to as "overclocking"? How clever. Enjoyed, Thanks for sharing.

[@hectorpascal]

Very interesting (and remarkably clean)! Well done! I've always thought those old metal can 2N2222 "switching" transistors are quite amazing devices, and will lend themselves to almost any application. Out of interest which of the many manufacturers who produced it, made the 2222's you used?

I can see in the video that the official power measuring device was a QRPometer, designed by Dave Cripe NM0S.

[@Randrew]

I was wondering why the certificate said David Cripe was the president of N-type Metal Oxide Semiconductor. Ha! That was a 0, not an Oh.

[@joeteejoetee]

Where can I buy one of these?

[@d.jensen5153]

I love this sort of contest, and Hans has knocked it out of the ballpark.

[@JxH]

When I saw the two coppers tubes, I immediately assumed that you had implemented 'heat pipe' technology. It seems that you haven't. Heat pipes would be a simple modification: Ensure that the 2N2222A transistors are tightly sealed into the tubes (already done that step I'll bet), then add a phase change fluid/gas, and turn the assembly vertical (2N2222A at the bottom), and add additional heat sink area at the top. Pressure in the tubes might need adjustment, depending on the fluid/gas chosen. The liquid phase fluid will boil and carry away heat to the top, where it'll condense and flow down to repeat the cycle. Heat pipes can carry away many times the heat of a normal copper pipe. Temperature should be stable and thus power could be nudged up further.
For additional ideas, look into the crazy computer 'Overclockers'.

[@Paul_VK3HN]

Wonderful effort Hans, so much fun when amplifier theory and practice come together in something like this. Loved seeing the device under a perspex safety cover, in case of 2N2222A thermo non nuclear destruction!

[@Steve-GM0HUU]

👍Well done Hans and thanks for sharing. I remember a while back wondering if I could build a XTAL controlled astable RF multivibrator TX. I think an audio astable multivibrator was one of my first projects as a kid 😊. I wondered about using BC107s or IRF510s. Using transistors that can handle the current without the crazy big heatsinks might make for a useful simple QRP TX circuit that would give a few Watts out? I wonder if you tested your 2N2222A TX on air? Perhaps how it sounded in terms of chirp?

[@joeteejoetee]

Thank you very much for this very technically detailed video. Bravo. 73's !
KJ4QJF

[@2000freefuel]

I'd love to see something like this with a dual section thermionic valve!

[@N2AIE]

Also see my colleagues from Collins ARC in the Background

[@TheArtofEngineering]

I love nerds!!!

[@vk3ye]

Thanks Hans - an inspiration. Apart from the crystal the circuit appears quite similar to the Kalitron oscillator as featured in various RSGB books from the '60s & 70s. My brief experiences is that they start up reliably when free running. Over a wide frequency range too. I wonder what power you could get out from one using BD139s, or maybe a Darlington pair arrangement.

[@vk3ye]

Hans - another thought. There's balanced mixer circuits not unlike this oscillator. I wonder if it would be possible to operate it as a balanced mixer simultaneously with oscillating. Then it could form the basis of a simple DC CW transceiver driving a crystal earpiece (with extra audio amplification needed).

[@markusm.lambers8893]

Concratulations Hans!
I thought that the 5W on the QCX and Co, are a good choice, to have a simple and effective PA. But I have to 'replace' my mind! This is far, the more interesting way, ... !
"We salute you!"
73/72 de Markus ; db9pz

[@everettcatlin4328]

Congratulations Hans DE WA2BHS

[@michaelmccarty2928]

Are you planning on entering the 2024 contest? If so how much power are you up to?
Thanks DE KE5RJJ