[Amps] DEAD Alpha 91B

[Thomas Carlsson]

ALPHA 91b has the fan connected to (almost) the center tap.In original
version is is connected to the 100V level and the manual suggest it to be
moved to the 120V level (the real center tap) for 220V 50HZ operation - or
move it anyhow if you can tolerate more fan noise and allow to push more
air.


On Mon, May 18, 2009 at 1:34 PM, Carl <km1h at jeremy.mv.com> wrote:

> I believe the Alpha 77 series were the last to violate NEC but not the
> only company do do so.
>
> Carl
> KM1H
>
>
>
> ----- Original Message -----
> From: "Jim Brown" <jim at audiosystemsgroup.com>
> To: <amps at contesting.com>
> Sent: Monday, May 18, 2009 12:03 PM
> Subject: Re: [Amps] DEAD Alpha 91B
>
>
> > On Mon, 18 May 2009 12:33:19 -0300, Thomas Carlsson wrote:
> >
> >>The Alpha 91b is a great amplifier
> >
> > Mike,
> >
> > While you're in there, you might want to check to see if this model
> > is running a 120V fan between one side of 240V and ground. As you
> > know, that's a no-no, and generates problems with magnetic fields.
> > Alpha does that with some of their older amps. Ten Tec solved that
> > design problem correctly by running their 120V fan off of half of
> > the primary of the power transformer.
> >
> > 73,
> >
> > Jim K9YC
> >
> >
> > _______________________________________________
> > Amps mailing list
> > Amps at contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>



-- 
Thomas, PY2ZXU/SM0CXU
Member of the PW2D Team