[Amps] SGC-Mini Lini

[Fuqua, Bill L]

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

_______________________________________________
Amps mailing list
Amps at contesting.com
http://lists.contesting.com/mailman/listinfo/amps