The AM Forum

http://www.arrl.org/qex/2005/qx11carcia.pdf

Congratulations to Frank, WA1GFZ who successfully built, tested and wrote a full featured, nicely photographed article about his 1500W class E amplifier for QEX magazine. It appears in this month's issue and is available on the ARRL site as a free sample. [the ONLY free sample for November/Dec 2005 issue]  Hit the link above to check it out. You do not need to be a member to see it.

It was edited by John/W3JN. Well written article and very informative.  If I were an ARRL tech editor, I wud be very proud to feature it.

Nice to see one of our own in the limelight like this!

Again, great job, Franz!!  [Use one of those shots as your new avatar... ;D]

73,
Tom, K1JJ

Congratulations, Frank!  And hats off to the editing and testing team, too. 

TNX Guys
It was a pile of work to publish in QEX. John threw in some interesting thoughts and the test at Steve's was an event. Even though we were at the limit of stability one Bird 43 read 1 KW carrier and the other hit 5 KW peak.
Now to get off my lazy butt and finish the modulator.

Excellent work Frank! Very impressive!... I think I mentioned to you a while back, I wanted to try a linear amp using these devices. This article will be a great starting point for that project.

Thanks!....

PS.... now everyone will know what your avatar is!  ;D

Glen,
I found a guy who built a 6 M linear with IRF520s push pull parallel. 500 watts.
Imagine about 120 VDC and some positive bias with a low pass filter.
I would think a fan would be required to hit QRO.

TNX for the kind words. It was a lot of work and time to get the article complete. I did it in my spare time while not playing builder.
BTW, I just was thinking of you as I walked through our other lab.
2 big HP power supplies sitting in the bottom of 2 racksl......

Really? IRF520's? what about all that capacitance??


Oh oh oh oh!!!!.... Frank!... you really need to mark those right away "Scrap... do not inventory" and ship them down to North Carolina!!  :D :D

http://home24.inet.tele.dk/oz1pif/index.htm

Glenn check this out. 6 M linear. I would add a little feedback myself.
Very nice job! 

Interesting (IRF510's) still don't understand how it can work at 50mhz with all that internal capacitance  ???

Take a look at the specs for an MRF150 FET. I bet it is similar to the 510.
Actually the limiting factor is lead and wire bond inductance.
Back in '83 I was playing with IRF250 pulse drivers and observed 80 MHz oscillations as the gate went through the switch point and I became hooked on FETs.

Congratulations on the outstanding article, Frank!  Definitely a step forward int he class e world.

73 John

Tnx John
Your " see what it will dish out" rif still makes me smile.  fc

Pity is, the article does not appear in QST.  Members in good standing still have to pay extra for a subscription to QEX.  QST has degenerated to a pathetic rag full of drivel and of course, ads.

Outstanding! It reads very nicely with lots of detail and has a nice scientific point of view. Not to mention that's it's a very nicely designed deck!  :D

Thanks for the kind words Bill,
BTW, I save every driver article you do. As you know the driver seems a bigger deal than the final. fc

Frank:

Excellent article!

You should be proud.

Thanks for doing it too!

Dan
W1DAN

Great job Frank. Congratulations!

AH the nice check from the ARRL just paid for the rest of the wall insulation I needed and Home Depot has a $75 rebate. "Even losers get lucky sometimes"

Hey Frank,
You did a nice job. Looks like a lot of time was spent on both the amp and the article.

Regards,
BobbyT

Hey Guys,
The NU2B  class E program for determining tank and shunt values was checked with a number of different operating Qs and the measured results were very close to his program calculations. It should be stored here as a reference
fc