Martin,
The problem with air is that to cool a space as small as a chip, and yet
remove perhaps 80 watts of power from that confined space, requires
substantial amounts of air. This is more than can be moved through the
small passages unless you use high pressure. The thermodynamics just don't
work out.
That's why you use liquids instead. Of course, you must use materials
(additives) that prevent the growth of the green things (although of course
actual green stuff doesn't grow in the absence of light). Still, other
things do grow, but additives prevent this.
A good source of chilling is to use a Thermoelectric cooler. This is easily
done with the DC power supplies we all have in the shack.
----- Original Message -----
From: "Martin Ewing" <martin@aa6e.net>
To: "Gary Hoffman" <ghoffman@spacetech.com>; <tentec@contesting.com>
Sent: Monday, January 19, 2004 6:54 PM
Subject: Re: [TenTec] Quieting fan
> This seems off-topic, but anyway...
>
> Some of the larger xmtr tubes have water cooling jackets; they must
predate the
> PC. So, nothing new here, except applying it to transistor finals.
>
> You need a source of "chilled water" for this technique. You have to
worry
> about green stuff growing in the water, spills, etc.
>
> I have toyed with the idea of making an air distribution system, with a
squirrel
> cage blower/compressor in an acoustically isolated place. Pump in large
volume,
> relatively low pressure air instead of making noise with small fans. This
is
> pipe organ technology.
>
> Has anyone done it in a ham environment?
>
> 73 - Martin AA6E
>
> Gary Hoffman wrote:
> > I design these kinds of things. Much more compact than a heater core,
and
> > no fan, and much cooler.
> >
> > ok....end of shameless plug ! :)
> >
> > Seriously, these work for radios too, and you can totally get rid of
fans if
> > you want to.
> >
> > Regards,
> >
> > Gary
> >
> > ----- Original Message -----
> > From: "Gary Smith" <mandolinist@ameritech.net>
> > To: <tentec@contesting.com>
> > Sent: Monday, January 19, 2004 5:20 PM
> > Subject: Re: [TenTec] Quieting fan
> >
> >
> >
> >>I rarely chirp in but I do as many "power" computer users do & that's
> >>"water cooling" on my computer. There's a large market for these kind of
> >>heat sinks & in short what is done is to have water replace air as the
> >
> > heat
> >
> >>sink cooling media. An in-line water pump pushes water through the
> >>"water block aka heat sink" and it's cooled remotely by a 120MM fan
> >>blowing through an automotive heater core.
> >>
> >>Water is far more efficient than air for cooling so you get temperatures
> >
> > of
> >
> >>about 4 degrees C maximum over ambient room temperature from a
> >>processor running 80 watts.
> >>
> >>Yeah... I know it's too much for most people to deal with & no, you
don't
> >>get water inside your equipment... but your computer is dead silent
> >>except for the sound of the drives. If you were to do this with a radio
> >>it would be the same, no fan noise.
> >>
> >>Do a google search for water cooling on computers & you'll enjoy the
read.
> >>
> >>Gary
> >>ka1j
> >>
> >>Also, if someone knows the whereabouts of an Alpha 77SX with the serial
> >>2931 it's mine & I want it back. I sent it to Alpha when it was owned by
> >>ETO & it was never returned after they moved from Colorado Springs.
> >>Yes, I have all the documentation.
> >>
> >>
> >>
> >>>Hi,
> >>>
> >>>I lost the message that I am referring to. Someone said they put a
> >>>resistor in series with the fan motor in order to make it run quieter.
> >>>How do you determine that there is still sufficient air flow to
> >>>properly cool the tubes? What about in a warmer time of year? What if
> >>>you (or future owner of the amplifier, or would it be ampli-fire)
> >>>moved to a higher altitude QTH and left the resistor in circuit? I
> >>>understand the desire to make the amplifier run quieter, but obviously
> >>>there are other important considerations. You could just disconnect
> >>>the fan altogether and it would be silent, but of course then it would
> >>>not perform it's intended purpose.
> >>
> >>Gary
> >>
> >>Gary Smith
> >>CQ DX de KA1J
> >>http://musician.dyndns.org
> >>http://musician.dyndns.org/homebrew.html
> >>
> >>If you pick up a starving dog and make him prosperous, he will not
> >>bite you. This is the principal difference between a dog and a man.
> >>
> >>- Mark Twain -
> >>
> >>
> >>_______________________________________________
> >>TenTec mailing list
> >>TenTec@contesting.com
> >>http://lists.contesting.com/mailman/listinfo/tentec
> >>
> >>
> >
> >
> >
> >
> > _______________________________________________
> > TenTec mailing list
> > TenTec@contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
>
>
>
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