Aluminum window screen pinched between the glass frame & front panel will work
nicely. In fact, I
just helped a guy out with a homebrew 3-500 amp where most of the cover was
made out of screen.
Obviously, he had to provide a means for cooling the tubes, so he used glass
chimneys with a
pressurized chassis under the tubes. It really looks cool in the darkened
shack!!!
Joe,
N3JI
--- Alek Petkovic <vk6apk@eon.net.au> wrote:
> At 10:22 AM 29/02/2004 -0500, Ed Briggs wrote:
> >Regarding glass windows, I've seen them in pictures, and always wanted an
> >amp with one, but was always concerned about RF leakage and the possibility
> >of long term exposure to VHF harmonics, particularly when I got up close to
> >the window to admire the tubes.
> >
> >Are there practical techniques to safeguard against these issues in HF amps?
> >I like the way a 4-1000a looks too..
>
>
>
> Surely, a front door glass and screen from a microwave oven would do the
> trick.
>
> Alek, VK6APK
>
>
> >(The emphasis here is on safe nostalgia, not contemporary design
> >techniques.)
> >
> >Regards to all
> >
> >Ed
> >----- Original Message -----
> >From: "Mike McCarthy, W1NR" <w1nr@eecorp.com>
> >To: "P. Coppin" <copa054@cira.it>; <Amps@contesting.com>
> >Sent: Saturday, February 28, 2004 9:26 AM
> >Subject: RE: [Amps] 2 x 8877
> >
> >
> > > The Alpha SX had issues on 10M because of the capacitance of the two
> > > tubes. Also, 2x8877 is more expensive than 3x3cx800. With the 3cx800,
> > > the plate voltage is lower, required capacitance is lower, voltage
> > > ratings of tank components is lower translating into a more cost
> > > effective design.
> > >
> > > Still, nothing impresses me more, at least visually, than a pair of
> > > 4-1000's built into a cabinet with windows...
> > >
> > > Mike, W1NR
> > >
> > >
> > > -----Original Message-----
> > > From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]On
> > > Behalf Of P. Coppin
> > > Sent: Friday, February 27, 2004 8:29 AM
> > > To: Amps@contesting.com
> > > Subject: [Amps] 2 x 8877
> > >
> > >
> > >
> > > First of all, sorry for my poor english.
> > >
> > > I would like to know the reason why the amps manifacturers build linear
> > > amps
> > > using three 3cx800a7, 2 3cx1200a7, one 3cx3000a7 and ruskies but no one
> > > build a linear amplifire with 2 3cx1500a7 (8877) such as the Alpha sx.
> > > What problems they could have ?
> > >
> > > 73
> > > Paul i8ixo
> > >
> > >
> > > _______________________________________________
> > > Amps mailing list
> > > Amps@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/amps
> > >
> > >
> > >
> > > _______________________________________________
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> > > Amps@contesting.com
> > > http://lists.contesting.com/mailman/listinfo/amps
> >
> >_______________________________________________
> >Amps mailing list
> >Amps@contesting.com
> >http://lists.contesting.com/mailman/listinfo/amps
>
> http://www.qrz.com/vk6apk
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>
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