This will get you the archive page.
http://archive.org/details/73-magazine-1962-02
73
Gary K4FMX
> -----Original Message-----
> From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Carel, pc5m
> Sent: Tuesday, November 13, 2012 4:39 PM
> To: amps@contesting.com; 'Radio WC6W'
> Subject: Re: [Amps] low Q output matching
>
> Thanks to all who responded to my initial question, very interesting to
> read
> the comments !. Much appreciated.
> Seems (as most of the time..) there isn't a free lunch served...Will
> just
> continue with some moderate Q (10 or so).
>
> Marv, if you could scan the article ? I suppose a 50 year old legacy one
> will infringe copyright much...
> Thanks in advance,
> 73's Carel, pc5m.
>
>
> -----Original Message-----
> From: Radio WC6W [mailto:wc6w_amps@yahoo.com]
> Sent: dinsdag 13 november 2012 17:58
> To: pc5mCarel; amps@contesting.com
> Subject: Re: [Amps] low Q output matching
>
> Hi Carel,
> There's an ancient article in the February 1962 issue of 73 Magazine,
> pp
> 12-19, that covers this topic in depth.
>
> If you can't run down an on line copy, I can have it scanned for you.
>
> 73 & Good morning,
> Marv WC6W
>
> http://qsl.net/wc6w/
>
>
> --- On Sat, 11/10/12, Carel, pc5m <pc5m@xs4all.nl> wrote:
>
> > From: Carel, pc5m <pc5m@xs4all.nl>
> > Subject: [Amps] low Q output matching
> > To: "'AMPS'" <amps@contesting.com>
> > Date: Saturday, November 10, 2012, 7:26 AM Hi, I was wondering what
> > else, besides bad harmonic suppression, will happen when I design my
> > (single band) output matching network
> > (PI-L) with low Q
> > (lowest Q needed to get the match done) ?
> >
> > When using low Q design I will get
> > - much smaller (variable) capacitors, especially for the bigger load
> > C, so easier to get components
> > - broader no-tune range
> > -smaller RF stress on the components
> >
> > As an example for a 160mtrs amp, with Rload of 1700Ohm and
> > intermediate impedance around 330Ohm:
> > With Q of 10:
> > CLoad =1200pF
> > L-l=10uH
> > Ctune=293pF
> > Lpi=33uH
> >
> >
> >
> > With lowest Q:
> >
> > CLoad=400pF
> > L-l=10uH
> > Ctune=132pF
> > Lpi=33uH
> >
> >
> >
> > When you plot both matching networks in a Smith diagram you see
> > immediate the difference. Low Q is much more straightforward.
> > To get the needed harmonic suppression a lowpass filter with fixed
> > components is easy to construct (first harmonic at 3,8MHz needs 25dB
> > and second one 20dB to get the same values as higher Q design).
> > But maybe I have
> > overlooked something . Thanks for your ideas 73's Carel, pc5m
> >
> >
> >
> >
> >
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
>
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