[AMRadio] Class E Transmitter Kit

[Bill Smith]

Hi, Steve

Please put me on the 80 meter list.  Perhaps 160, also.

Bill Smith, AB6MT
340 C Street
San Rafael, CA 94901
415-456-4481
billsmith at ispwest.com

Tnx & 73

Bill


----- Original Message -----
From: "Steve Cloutier, 978-597-3311" <cloutier at bicnet.net>
To: <amradio at mailman.qth.net>
Sent: Monday, June 24, 2002 6:02 PM
Subject: [AMRadio] Class E Transmitter Kit


> Hi!
>
> Another Amateur - Bob, K1KBW and myself (Steve, WA1QIX0 are developing a
> class E transmitter kit.
>
> The proposed kit will use a common modulator and power supply, and use
> seperate RF amplifiers - keeping the design simple.  RF amplifiers are
> proposed for 160, 80 and 40 meters.
>
> The power level will be between 300 and 400 watts carrier, probably around
> 350 watts [power input - efficiency is around 90%].  A single 6 MOSFET RF
> module is proposed.
>
> I am currently running 400 watts on 160, 80 and 40 meters using this
design.
>
> For the proposed class E transmitter kit, I have developed and built a
> class H analog modulator.  It is much simpler than previous designs, and
is
> easy to adjust.  I am currently using this modulator with my 400 watt
class
> E RF amplifiers, and the performance, stability and reliability is
excellent.
>
> Class H is high efficiency analog mode, where the power supply voltage
> supplied to the output device(s) is adjusted to provide more voltage to
the
> devices when
> more output voltage is required. Class H is similar to class G, where the
> supply voltages are stepped.
>
> This class H modulator is a simpler version of the so-called class B
series
> modulator which I had previously used. In addition to being simpler than
> the previous version, the audio performance is superior. This is the
> modulator I am proposing for the class E transmitter kit.
>
> The new modulator is *VERY* simple to adjust, and eliminates the most
> complex circuitry of the original class b series modulator. It will
operate
> over a wide range of input DC voltages and is very stable.
>
> The modulator uses a small floating driver consisting of a TL074 op amp.
> Audio input is fed to the floating op-amp in differential mode, referenced
> to ground. The
> driver op-amp floats along with the modulated DC. The modulated DC appears
> across the inputs of the floating op-amp in common mode. The op-amp
rejects
> common mode signals, leaving only the differential input signal - the
> audio. This circuit elminiates the need for DC isolation devices such as
> transformers or
> opto-couplers.
>
> Please check out the schematic if you're interested :-)  [link at bottom
of
> this message]
>
> I am seeking feedback, comments, suggestions, etc. relating to the class E
> kit, the design, packaging - whatever.  If you have anything to say,
> feelings, thoughts, etc.  *please* let them be heard.
>
> Something like this could be a big boost for AM.  We are doing everything
> we can to drive the price as low as possible - volume parts buys, offering
> different levels of kits [active components only, with heat sinks, with
> chassis, with power supply, etc. etc. etc.] to allow for flexibility.
>
> The class E web site [with schematics, etc.] is at:
>
> http://www.netway.com/~stevec/ham/classe.htm
>
> Thanks and Regards,
>
> Steve WA1QIX
>
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