Re: PWM Controller question

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Sue Gaeta <sgsparky-at-prodigy-dot-net> 

Hi Jim,

I just found this website, 
<http://www.classeradio-dot-com/>http://www.classeradio-dot-com/ and talk about 
information overload! Everything you want to know about the use of MOSFETs 
in transmitters and were afraid to ask! This is Steve WA1QIX's website. He 
is somewhat of a pioneer in using this technique in Amateur radio 
applications, at least on the East Coast of USA.

 From what I see on this page PDM (Pulse Duration Modulator) and PWM(Pulse 
Width Modulator) is the same animal.

This page looks like a valuable resource for those of us that want to 
modulate our coils.

Sue

Tesla list <tesla-at-pupman-dot-com> wrote:
Original poster: "Jim Lux"

Oddly, we were discussing just this at lunch today, in connection with 3885
kHz.
You could build one of the Class E amps a'la Rutledge, then audio modulate
the DC power supply.
We discussed various techniques for doing plate modulation w/o transformers
(or with physically small transformers), particularly for doing SSB.
PDM rigs or PWM rigs? Pulse Duration Modulation, I suspect.
----- Original Message -----
From: "Tesla list"
To:
Sent: Thursday, June 24, 2004 5:52 PM
Subject: Re: PWM Controller question


 > Original poster: Sue Gaeta
 >
 > Jim,
 >
 > Several years ago, a new breed of AMers started to show up on the 75 meter
 > ham band with "PDM rigs" that use Mosfets in their designs. They really
 > sound great, and I know they aren't modulating them with mod.
transformers,
 > but to be totally honest here, I haven't done enough research to find out
 > exactly what they are doing. If they sound that good, using transformers
to
 > modulate is not only bulky, and inconvinient, but absurd! The only good
 > thing about them is that you get complete isolation, and the circuitry is
 > less complex. However, I don't think complexity is an issue for those guys
 > that are pioneering this whole SSTC (and it's varients) movement.
 >
 > I am a follower rather than a leader. Show me a schematic and I will build
 > it! Although my friend has built many transmitters with vacuum tubes, and
 > is perfectly capable of installing and operating the most modern
 > transmitter equipment all the way up to 100KW, he has never delved into
the
 > inner workings of those solid state transmitters, so I can only g! et vacuum
 > tube help from him!
 >
 > Sue
 >
 > Tesla list wrote:
 > Original poster: "Jim Lux"