I got the idea from a very special place :) The tube's Data Sheet that
recommends
a specific set of operational parameters for SSB AB Class. The output is set
at 1500W under these conditions. It somebody is doing more than that it
means that they do not respect the manufacturers specifications.
So... How do you get 2000+ from a design that is aimed to 1500 and still
keeping the intended signal purity ?
Alex, N2NNU
----- Original Message -----
From: "Steve Katz" <stevek@jmr.com>
To: "'alex'" <alex@sandlabs.com>; <amps@contesting.com>
Sent: Monday, December 03, 2001 7:43 PM
Subject: RE: [AMPS] AL1500
>
> Where did you get the idea that an 8877 can "deliver safety only 1500W?"
> It's a 1500W rated _dissipation_ triode. Normally, one can achieve about
2x
> the plate dissipation rating of any transmitting tube operating in linear
> ICAS. 8877's are used in broadcast service in the FM band at 2000W
carrier
> power output, continuously, albeit with larger power supplies and cooling
> systems than you'll find in amateur amplifiers, and running Class C.
> 3CX800's and 4CX800's, having only 53% of the dissipation rating of the
> 8877, are commonly found and on the market running full amateur legal
limit
> output power.
>
> The internal cooling system in the AL1500 appears fine for > legal limit
> power, as the only thing getting hot during my testing was my Bird dummy
> load. The amp exhaust air stream gets quite warm, as would be expected,
but
> does not seem overly hot. I have a number of external anode (finned
cooler)
> amplifiers using 8874's, 4CX250's, 8122's, etc, and the AL1500 exhaust air
> is certainly no warmer than any of those (from Alpha/ETO, et al).
>
> If you're skeptical, I'd recommend you go with something else. But I've
had
> no problems with the Ameritron products from the AL80B to the AL1500 (and
> including the AL1200)...although admittedly haven't used the little ones
> like the AL811, etc.
>
> 73
>
> WB2WIK/6
>
>
>
> "Each success only buys an admission ticket to a more difficult
problem." --
> Henry Kissinger
>
> > -----Original Message-----
> > From: alex [SMTP:alex@sandlabs.com]
> > Sent: Monday, December 03, 2001 4:32 AM
> > To: Steve Katz; amps@contesting.com
> > Subject: Re: [AMPS] AL1500
> >
> > This is interesting... The tube, I understand, can deliver safely only
> > 1500W.
> > How do you get so much more... And how about cooling... Is the internal
> > blower enough at these power levels ?
> >
> > Alex, N2NNU
> >
> >
> >
> >
> > ----- Original Message -----
> > From: "Steve Katz" <stevek@jmr.com>
> > To: "'alex'" <alex@sandlabs.com>; <amps@contesting.com>
> > Sent: Monday, December 03, 2001 4:42 PM
> > Subject: RE: [AMPS] AL1500
> >
> >
> > >
> > > Is that a French ham or a Function key? <yuck>
> > >
> > >
> > > > A friend of mine, an F3... , (has no internet access) wants to know:
> > > >
> > > > Does anyone know what the AL1500 is _really_ capable and under what
> > > > conditions?
> > > [Steve Katz] The AL1500 runs a lot of power. Not so much for
> > > people using "tetrodes with handles," but more than the amateur legal
> > limit,
> > > for sure. Had one on the bench churning 2200W carrier power for
(yawn)
> > > about ten minutes before I decided that was enough garage heating for
> > the
> > > day. Besides, my Bird 1200W load was getting rather toasty. I don't
> > doubt
> > > for a moment that it can run 1500W output continuously (not
necessarily
> > in
> > > the broadcast sense, but in the amateur sense).
> > >
> > > WB2WIK/6
> > >
> > >
> > > > I have no experience with it, so perhaps somebody in the group could
> > help
> > > > him.
> > > > TIA, Alex
> > > > N2NNU
> > > >
> > > >
> > > >
> > > >
> > > > --
> > > > FAQ on WWW: http://www.contesting.com/FAQ/amps
> > > > Submissions: amps@contesting.com
> > > > Administrative requests: amps-REQUEST@contesting.com
> > > > Problems: owner-amps@contesting.com
> > >
> > > --
> > > FAQ on WWW: http://www.contesting.com/FAQ/amps
> > > Submissions: amps@contesting.com
> > > Administrative requests: amps-REQUEST@contesting.com
> > > Problems: owner-amps@contesting.com
> > >
>
> --
> FAQ on WWW: http://www.contesting.com/FAQ/amps
> Submissions: amps@contesting.com
> Administrative requests: amps-REQUEST@contesting.com
> Problems: owner-amps@contesting.com
>
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|