[Amps] SGC-Mini Lini

[Radio WC6W]

Hi Bill,
  Yes, the delay between the Carrier and the Modulation has to be equalized somewhere...

  The original Kahn scheme implemented
 it at a fixed frequency with an LC delay.

  In the 21st century, one can either externally preprocess the audio with a bit of DSP in conjunction with a typical transceiver, or build a whole exciter with the proper delays incorporated;  The latter is more easily realized.

73 & Good afternoon,
  Marv WC6W 

http://wc6w.50webs.com/
  


--- On Sun, 8/9/09, Fuqua, Bill L <wlfuqu00 at uky.edu> wrote:

> From: Fuqua, Bill L <wlfuqu00 at uky.edu>
> Subject: Re: [Amps] SGC-Mini Lini
> To: "ToddRoberts2001 at aol.com" <ToddRoberts2001 at aol.com>, "amps at contesting.com" <amps at contesting.com>
> Date: Sunday, August 9, 2009, 9:40 PM
> Well, I think the contact problem
> was  the least of their worries. I suspect the is a
> fundamental problem with the product which I don't believe
> they ever overcame. To accurately reproduce a ssb signal you
> need to accurately reproduce both the amplitude and phase
> simultaneously. It is no problem with AM but is with SSB.
> Some of you may remember the Central Electronics SSB
> products, they had two balanced modulators and one you could
> throw out of balance to produce AM and the other PM. But, in
> a since it took both to produce PHASE and AMPLITUDE
> information to produce an SSB signal. 
>   The problem with the Mini Lini was that since they
> used a switching power supply/modulator the amplitude
> information was delayed in the processing to PWM and then in
> the filtering that followed and  the signal from
> the  class-E amplifier was amplitude and phase
> modulated but they were no longer in time sync. and under
> dynamic situation spurious signals would appear above and
> below the intended frequency. They could have used a linear
> modulator and overcame the problem but the efficiency would
> then be no better than a Class AB transistor
> amplifier.  Also there may be issues with phase shifts
> within the class E amplifier as it is amplitude
> modulated.  The class E amplifier is in a way similar
> to the DAF amplifier and I always had mixed feelings about
> that one. And I suspect that it's IMD products are dependent
> on the filtering between the screen modulator and the screen
> grid along with the modulators linearity. 
>   Tonight seeing the stuff on the other SGC amplifier
> I came up with a possible solution but I was hoping that I
> could find one out there to experiment on. Having more free
> time now days I may have time to investigate these things, I
> hope. 
> 
> 73
> Bill wa4lav
> 
> ________________________________________
> From: amps-bounces at contesting.com
> [amps-bounces at contesting.com]
> On Behalf Of ToddRoberts2001 at aol.com
> [ToddRoberts2001 at aol.com]
> Sent: Sunday, August 09, 2009 10:54 PM
> To: amps at contesting.com
> Subject: Re: [Amps] SGC-Mini Lini
> 
> In a message dated 8/9/2009 10:26:25 P.M.  Eastern
> Daylight Time, wlfu
> qu00 at uky.edu writes:
> 
> Does anyone out there  actually own a Mini Lini?
> 
> 73
> Bill  wa4lav
> ______________________________________________________________
> 
> I  don't think SGC ever actually produced any of the
> Mini-Linis for sale.
> They  had reliability problems with the plug-in band
> modules
> that used banana plugs  and sockets and problems with
> the
> output spectrum.  The owner of SGC  died a year
> or two ago I think
> and they never finished the 
> product.   SGC
> is still in business though selling tuners, some ham 
> accessories
> and the 500 watt linear amplifier the SmartPowerCube.
> 
> The Mini-Lini used a Class-E
> amplifier and EER to amplify an  SSB signal.
> Apparently
> they never overcame some technical problems  with it
> to make it cost effective to market.
> 
> I'm surprised no one  else has come up with a
> commercial
> Class-E amplifier yet for the Ham  Bands.
> 
> 73 Todd WD4NGG
> 
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