Amps
[Top] [All Lists]

Re: [Amps] LA100 tuner for input to amp (Not LP100)

To: "'Jim'" <jimw7ry@gmail.com>, <amps@contesting.com>
Subject: Re: [Amps] LA100 tuner for input to amp (Not LP100)
From: "Jim Garland" <4cx250b@miamioh.edu>
Date: Sun, 15 Mar 2020 16:19:09 -0600
List-post: <mailto:amps@contesting.com>
As Jim mentioned, in 2006 LDG briefly sold an autotuner designed to match
input networks of cathode driven homebrew amplifiers. The model was the
AT-100AMP, a similar design to the  LDG LA100 autotuner and rated at 1-125
Watts.  At the time, I and my buddies Jerry K8RA (SK) and Dan K8DR, all
amplifier builders, bought several of the units, priced at $125/ea, for our
own projects. They simplified construction of a homebrew amplifier by
eliminating the need to gang the tank and input circuits together in order
to use a single knob for bandswitching. They worked very well, and to my
knowledge are still in use somewhere.

I bought two of the tuners for future projects, and recently gave one to my
buddy Bob, KK5QM, who just completed a lovely 80-10m amplifier running two
3CX800A7s. I'm saving the second one for a homebrew 8877 autotune amplifier
I'm currently building. My new amp uses a powerful eight-core processor that
hugely consolidates and simplifies the controller hardware. The software and
controller hardware are now mostly working, but assuming COVID-19 doesn't
get me first, the entire project is likely to take a couple of years to
finish. I envisage it as basically a modernized Alpha 9500 on steroids.
73,
Jim W8ZR

> -----Original Message-----
> From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Jim
> Sent: Sunday, March 15, 2020 11:49 AM
> To: amps@contesting.com
> Subject: Re: [Amps] LA100 tuner for input to amp (Not LP100)
> 
> It was written by Jerry Pittigner, K8RA now a Silent Key. His amplifier
> was in one of the ARRL handbooks as a 3cx1200Z7 amplifier project.
> 
> I tried to use one on a 2ea 3CX800 amplifier and did not like its
> performance.
> 
> Went to an input board with variable caps on both input and output.
> 
> 
> Thanks
> 73
> Jim W7RY
> 
> On 3/14/2020 5:37 PM, Robert wrote:
> >
> >
> > In the 2006 ARRL Handbook is article on HB 3CX1500D7 amp.   This amp
uses a
> > LDG antenna tuner for the input circuit.
> >
> > A modified LA-100Pro
> >
> >
> >
> > It's not possible from the article to determine who the author is.
> >
> >
> >
> > Who wrote the article?  is first Question.
> >
> >
> >
> > And if he's on list, still like the LA100 being used as tuned input??
> >
> > seems like viable path for my next HB project.
> >
> >
> >
> > 73 W5AJ
> >
> >
> >
> >
> >
> > Robert
> >
> > Midland, Texas
> >
> >
> >
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> 
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps

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

<Prev in Thread] Current Thread [Next in Thread>