[Heathkit] foldback

Fri, 10 Oct 2003 11:49:14 -0400

> Perhaps you could shed some light on the SB-220 input impedance problem

I already did but I guess you didnt bother reading that post.

> instead of just bashing someone else.

Trying to present a balanced discussion is now called bashing? Gee and I
thought the purpose here was to help people and possibly not make expensive
mistakes. Sorry, go on your merry way ostrich style.

I have found Rich Measures to be of
> much more help than QST.

He has some good advice.

>
> And considering most of the stuff in QST, it is probably a high honor NOT
to
> be published there.

Obviously you are totally clueless what transpired and are not interested in
anything but QST bashing and your own beliefs.

Enjoy yourself

Carl

>
> 73, Mike N4NT
>
> ----- Original Message ----- 
> From: "Carl" <[email protected]>
> To: <[email protected]>
> Sent: Tuesday, October 07, 2003 10:37 PM
> Subject: Re: [Heathkit] foldback
>
>
> > You may want to read the series of rebuttals by real engineers in QST
> about
> > the Measures articles. And that he has been banned from future
publication
> > there.
> > I consider most of his parasitic theory pure garbage and have proven it
> time
> > and again to skeptics. This is old news as it took place on the AMPS
> > reflector several years ago.
> >
> >
> > Carl
> > KM1H
> >
> >
> >
> > ----- Original Message ----- 
> > From: "David Cook" <[email protected]>
> > To: "'Jim Brannigan'" <[email protected]>;
<[email protected]>
> > Sent: Tuesday, October 07, 2003 9:48 PM
> > Subject: RE: [Heathkit] foldback
> >
> >
> > > Wow, what a great paper! I recently acquired the first amplifier I've
> ever
> > > owned, an SB-200. I put in all the Harbach mods, but still didn't
> > understand
> > > much about it. Many of Rich's explanations of the design decisions and
> > > performance considerations for the SB-220 apply to the SB-200. Thanks
> for
> > > posting this link. I'm going to fire off an e-mail of appreciation to
> Rich
> > > as well.
> > >
> > > 73, Dave, WA�TTN
> > >
> > > > -----Original Message-----
> > > > From: [email protected]
> > > > [mailto:[email protected]]On Behalf Of Jim Brannigan
> > > > Sent: Monday, October 06, 2003 2:38 PM
> > > > To: Hotmail; [email protected]
> > > > Subject: Re: [Heathkit] foldback
> > > >
> > > >
> > > > This is Rich Measures' site.  There is a wealth of information on
the
> > > > SB-220.
> > > > http://www.somis.org/sb220ci.html
> > > >
> > > > The SB-220 was designed when most exciters were tube based
> > > > with a pi-network
> > > > output.  The pi net output is able to match a wide range of
> > > > loads and the
> > > > input impedance of the amplifier was not a serious design
> > > > consideration.
> > > > Many Solid state exciters are not as forgiving and some
> > > > attention to the
> > > > amplifier input impedance is necessary.
> > > >
> > > > Jim
> > > >
> > > >
> > > > ----- Original Message -----
> > > > From: "Hotmail" <[email protected]>
> > > > To: <[email protected]>
> > > > Sent: Sunday, October 05, 2003 12:10
> > > > Subject: [Heathkit] foldback
> > > >
> > > >
> > > > > I have a great SB220 with the latest Harbauch mods that I
installed.
> > > > >
> > > > > Question:
> > > > >
> > > > > My exciter (TS140S) folds back to 50 watts out on 10
> > > > meters. How do I go
> > > > about tuning the amplifier (input circuit I guess) to
> > > > eliminate the foldback
> > > > issue or is this normal?
> > > > >
> > > > > Thank you,
> > > > >
> > > > > Bruce
>
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