One 11N90 or IRFP260N MOSFET mobile amp?

[K1JJ]

A couple of years ago a few guys were experimenting with one and two MOSFET (11N90 or IRFP260N ) mobile amps.  

I need a simple one MOSFET  IPA that will take a few watts from my ricebox and bring it up to ~40 watts of carrier to drive my class C  4-1000A rig. The ricebox is being overtaxed. Does anyone have a working circuit and pictures of these very simple mobile amps?

A 24V class C design for a single MOSFET will do the trick.  I am talking maybe 100w pep max needed.  It can be class C  and without filtering cuz the 4X1 grid tank and plate tank will filter out any crud.

Hopefully it can be small, like 3" X 3", to fit right inside the 4X1 rig.

T

[KK4YY]

Tom,

Your request reminded me of this article I read a while back:
http://www.golddredgervideo.com/kc0wox/wa2ebyamp/amppart1.pdf
Is that what you were looking for?

-Don

[W1RKW]

Tom,
I have something that may be of interest.  It's a single transistor. About 2w in and about 40w out. I believe it is class C. Can't remember if its a FET or BJT. It uses transmission line transformers. It didn't use coax as the transformer but twisted pair. I have to do some digging but it's a solid little rig. Came from an ARRL pub and was powered by 12v vice 24V.  I still have the amp but I don't know about the paperwork. It might have gotten displaced in the move here 12+ years ago. Can't remember what pub it came from. Could have been from one of their older Solid State Design books. I might be able to reverse engineer it with pics.

[K1JJ]

Thanks for the info, guys.  I'll bet either of your ideas would work.

In the meantime, I pulled out an old CCI  quad MRF-150 MOSFET linear amp board I have. (EB-104)  It is good for 600 watts at 50V, 160-10M.   It has one blown FET, but with three it is still putting out about 20dB of gain.   With a sig gen and 12V  I saw about 15 watts.  This thing is mounted on a copper spreader and I may add a small fan. So, 40 watts shud be no problem.  Still messing with it.

Thanks for the suggestions.

T