I have an AL-811H that was given to me. Had to replace the tubes and have had
nothing but problems. I can't get the amp to neutralize no mater what I do. I
haven't tried 572B's yet. Sure wish I could get some of those USA made tubes.
Hal
________________________________
From: Charles Mills <w3yni1@gmail.com>
To: Carl <km1h@jeremy.mv.com>
Cc: amps@contesting.com
Sent: Monday, February 27, 2012 2:16 AM
Subject: Re: [Amps] AL-811H
I use a set of JAN 811 tubes that I picked up from Surplussales.
Also a ham friend of mine used his Greenlee punches to cut a whole in the
side for a fan to blow across the tubes and keep them cooler and aid in
ventilation with another 4"x4" hole on top (screened of course).
chuck/w3yni
On Sun, Feb 26, 2012 at 9:13 PM, Carl <km1h@jeremy.mv.com> wrote:
> I havent had any H's come thru here that werent neutralized but extended
> tuning does cook the suppressors on 10M.
>
> I tear out that stuff and wrap the original coil around one of a pair of
> 100
> Ohm Ohmite OY series resistors in parallel.
>
> All the AL-811 family are quite unreliable due to a combination of bad
> tubes
> from China, design, and QC. It is not on my recommended list unless its
> dirt
> cheap and you use 572B's.
>
> Carl
> KM1H
>
>
>
>
>
>
> ----- Original Message -----
> From: "Tom Osborne" <w7why@frontier.com>
> To: <amps@contesting.com>
> Sent: Sunday, February 26, 2012 7:12 PM
> Subject: Re: [Amps] AL-811H
>
>
> > Thanks for the info. I have a friend here who has one about a year old
> > and was wondering about that. 73
> > Tom W7WHY
> >
> >
> >
> >
> > The newer ones have a whole different suppressor scheme than the older
> > ones. if this is an older amp you can update it with the new parasitic
> > board designed for the newer 811H amps. If this is a newer amp and
> already
> > has the updated suppressor board then there may be a different issue.
> The
> > older 811H amps I don't think were neutralized. The newer 811H amps are
> > neutralized.
> >
> >
> > In a message dated 2/26/2012 6:55:57 P.M. Eastern Standard Time,
> > w7why@frontier.com writes:
> > On the 3830 contest reflector someone posted a comment that "The AL-811H
> > has
> > a know problem of the parasitic chokes burning up on 10 meters." Is that
> > a
> > true fact on those amps? 73
> > Tom W7WHY
> >
> >
> >
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> >
> > -----
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>
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