[Amps] SS Amp Design/Plans (was Elecraft Amplifier...)

[Will Matney]

Joe,

I tried to find those schematics I seen on the net but just couldn't find them anywhere. There is a really good book on the subject named "Practical RF Communications Data" by Doug DeMaw. The ISBN Number is 0-672-21557-8 and was printed by Sams. It goes into detail abount designing solid state amps using either transistors of FET's. If you can locate a copy, I think it would be what you want.

Best,

Will

*********** REPLY SEPARATOR  ***********

On 4/25/05 at 1:29 PM Joe Isabella wrote:

>I want to build one, not buy one.  I'd like to find plans for something
>meeting the specs below.
> 
>However, I have made a little progress with this endeavor.  I friend of
>mine is nearing completion of his EE degree and needs a project, so I
>suggested this idea.  We'll see how it goes -- he seemed quite interested.
> 
>Joe, N3JI
>
>"Carcia, Francis A HS" <francis.carcia at hs.utc.com> wrote:
>metron did an 800 watt 12 volt unit. A couple friends run them.
>
>-----Original Message-----
>From: Joe Isabella [mailto:n3ji at yahoo.com]
>Sent: Friday, April 22, 2005 1:57 PM
>To: Amps
>Subject: Re: [Amps] Elecraft Amplifier (was Re: Fwd:Re: More Rumors)
>
>
>So all this talk here about FETs and such, where can a layman like myself
>find plans for say, a 100W in/500-700W out 12V amp?? I'd like to build
>something along those lines for my mobile, but don't have the time to
>invest
>in learning to design my own...
>
>Thanks, Joe
>
>Dave Haupt wrote:
>Will,
>
>If you know anything about the Elecraft people, you
>would know that they would never "get by" with
>anything. Everything they do is top notch.
>
>It is possible to parallel FETs, but you're asking for
>a whole lot more work in the process of matching them.
>Even if your curve tracer shows that they're
>electrically matched, if they're not thermally
>matched, then once the amps starts delivering power,
>one device can begin to hog the current, and you see
>IMD rise precipitously.
>
>Directly parallelling FETs works marvelously well if
>they're on the same die, or packaged on the same
>thermal header (e.g. MRF154/MRF157), but if you care
>about IMD, it's not advisable to directly parallel
>separate FETs which may or may not have come from the
>same die lot.
>
>They are using the Advanced Power Devices. Head to
>that company's webpage, and read up the app notes. 
>K4XU is the chief apps engineer there, and Dick is a
>very sharp guy. Think of him as the next Helge
>Granberg, except that he's also earned his stripes in
>contesting, as well as having a great reputation in
>both the commercial (e.g. medical) amplifier field and
>broadcast amplifier field.
>
>73,
>
>Dave W8NF
>
>
>Will wrote:
>
>>Vic,
>
>>How many devices and or push pull pairs did they use
>>for the power 
>>involved? I
>>do know using FET's you can get by with one push-pull
>>circuit and 
>>paralell
>>FET's on both sides. This is a big advantage over
>>using transistors and 
>>having
>>multiple push-pull circuits with splitters and
>>combiners.
>
>>Best,
>
>>Will
>
>
>
>
>
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