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@uky.edu> wrote:
> From: Fuqua, Bill L <wlfuqu00@uky.edu>
> Subject: Re: [Amps] SGC-Mini Lini
> To: "ToddRoberts2001@aol.com" <ToddRoberts2001@aol.com>,
> "amps@contesting.com" <amps@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@contesting.com
> [amps-bounces@contesting.com]
> On Behalf Of ToddRoberts2001@aol.com
> [ToddRoberts2001@aol.com]
> Sent: Sunday, August 09, 2009 10:54 PM
> To: amps@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@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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