Very interesting thread...Thank you!
Philip LaMarche
LaMarche Enterprises, Inc.
www.w9dvm.com
727-944-3226
FAX 727-937-8834
K3 #1605
CCA 98 00827
CRA 1701
W9DVM
-----Original Message-----
From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
Behalf Of Joe Subich, W4TV
Sent: Friday, January 29, 2010 2:53 PM
To: 'Bill K2OWR'; 'Lee Buller'
Cc: amps@contesting.com
Subject: Re: [Amps] Good amp to buy
> I have never heard anyone say that the AL82 was prone to failure, or
> that the components were delicate or hard to find. In my opinion an
> amp like this, bult like a battleship, if run even a little
> conservatively, will serve one for many more years, without failure
> than amps like the SB220, TL922, or the others, all of which are
> underdesigned with components stressed close to their limits.
There is a HUGE difference between the design of the AL-82 and the SB-220,
TL-922, L-4B, etc. The AL-82 was designed in a regulatory environment with
1500 W PEP output (about 2300 W DC
input) while the SB-220, TL-922, L-4B, etc. were designed in an era where
the legal limit was 1000 W DC input. The older amps weren't "under
designed" - they were designed for the rules in effect at the time with a
reasonable safety factor as
shown by the amount of "abuse" they regularly survive.
The difference represents 50% more plate dissipation (heat), significantly
more stress on the band switch and plate choke, greater energy stored in the
filter capacitors, and higher fault currents.
Any user who regularly pushes the older amplifiers to 1500 W is courting
catastrophic failure. Will some amps let the user get away with abuse -
yes. I'd stack the L4B up against any of the "modern" amps (particularly
with some modern fixes like a faster T/R relay and low voltage PTT line) but
1500 W is still pushing the limits for devices designed for operation at
1000 W DC.
73,
... Joe, W4TV
> -----Original Message-----
> From: amps-bounces@contesting.com
> [mailto:amps-bounces@contesting.com] On Behalf Of Bill K2OWR
> Sent: Friday, January 29, 2010 2:19 PM
> To: Lee Buller
> Cc: amps@contesting.com
> Subject: Re: [Amps] Good amp to buy
>
>
> :::: Thanks for understanding Lee.
>
> I have never heard anyone say that the AL82 was prone to failure, or
> that the components were delicate or hard to find. In my opinion an
> amp like this, bult like a battleship, if run even a little
> conservatively, will serve one for many more years, without failure
> than amps like the SB220, TL922, or the others, all of which are
> underdesigned with components stressed close to their limits.
>
> BTW, none of those are made any longer, nor have they been for many
> years.
> My AL82 is 20 years old now and I expect will likely outlive me.
>
> Oh, and if you're a contester and can't fix your own amp, stick to the
> 811, or 572B type amps....all solid designs!
>
> BILL K2OWR.....I'm gonna pay for my words, I know:-(
>
>
>
> > Bill
> >
> > I too like the AL-82 and have not trouble with mine. But,
> I run mine
> > in
> > conservative mode and not full throttle. Nice amp, but
> like all amps they
> > need to be tuned properly. The QRO-2000 is a nice amp too,
> but I don't
> > think he makes many of them anymore.
> >
> > I do like the 3-500Z bottles for cost.
> >
> > Lee - K0WA
> >
> > In our day and age it seems that Common Sense is in short
> supply. If
> > you
> > don't have any Common Sense - get some Common Sense and use
> it. If you
> > can't find any Common Sense, ask for help from somebody who
> has some
> > Common Sense. Is Common Sense divine?
> >
> > Common Sense is the image of the Creator expressing
> revealed truth in
> > my
> > mind. - J. Wolf
> >
> >
> >
> >
> >> "... I'd like to weigh in on this.....
> > The Ameritron AL82 seems to me to be the most rugged and powerful
> > amplifier in the twin 3-500Z class.
> > The power supply alone makes all the others seem puny and
> the output is
> > higher than all others in this class.
> > They can be had for as little as $1200 used and are truly a
> contesters
> > dream
> > amplifier.
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
>
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