Being one that runs a bit of AM on the HF bands, the latest and greatest
solid state output stages is Class E. The advantages, very efficient, very
clean, very reliable and very high power.
Check with the folks on the AM Window for more info.
73
Bob, K4TAX
----- Original Message -----
From: "Ken Brown" <ken.d.brown@hawaiiantel.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Saturday, September 01, 2007 7:40 PM
Subject: Re: [TenTec] Final Amplifier Class
> John,
>
> The short answer is: It depends.
>
> Once upon a time it was standard procedure to run the final amplifier in
> an AM transmitter in class C. This works fine when the final amplifier
> is the stage that is modulated. A class B push pull modulator modulates
> the class C final RF amplifier and it produces a good AM signal. This is
> the way that most AM transmitters, both for broadcast and communications
> used to work.
>
> If an earlier low power stage is modulated, then all of the subsequent
> RF amplifier stages need to be linear. They could be class A, class AB,
> maybe even class B (probably not), but absolutely NOT class C. If the
> rig runs SSB as well as AM, then it almost certainly generates the SSB
> at a low level, and does not use a modulated final RF amplifier stage
> even when it is in AM mode. In that case the final RF amp must be
> linear, and is not class C.
>
> DE N6KB
>
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