How often do you plan to descale the amplifier and scrub off the lint?
Lee, w0vt
----- Original Message -----
You would may need to keep a small vacuum on the water to assure that it
vaporizes at a sufficiently low temperature. Also, most vapor phase anodes have
cubes or bumps on their surfaces to facilitate the boiling of the water. The
solid state devices are derated at starting at much lower temperatures than
water boils. Works well in tubes where the seal temp. limit is ofter around 200
degrees C.
73
Bill wa4lav
________________________________________
From: Amps [amps-bounces@contesting.com] on behalf of Jim Thomson
[jim.thom@telus.net]
Sent: Thursday, June 06, 2013 12:44 PM
To: amps@contesting.com
Subject: [Amps] Solid state amplifier cooling
Date: Thu, 6 Jun 2013 09:15:54 -0600
From: MU 4CX250B <4cx250b@miamioh.edu>
To: amps@contesting.com
Subject: Re: [Amps] Message-ID: <963402869080783179@unknownmsgid>
CSolid state amplifier cooling
Interesting idea, Bill. I wonder if folks on the reflector have tried
vapor phase cooling? In principle, that should be the most effective
cooling scheme of all, given the high latent heat of vaporization of
water. Of course, the devil is in the details, and the practicalities
might be too burdensome. This is an interesting discussion.
Jim w8zr
## Vapour phase is not as good as you think it is. If u look at any old paper
copy
of eimacs care and feeding, re vapour phase cooling., you will see that the max
effect
occurs at 135 C..and not 100 C. That entire section is not in the latest
online version,
too bad. 100 C is too high for SS devices..and 135 C is clearly way too much.
## Then you also have the problem with bubbles forming on the surface of
what ever you are trying to cool. Tubes made for vapour phase cooling
have rough surfaces, to break up the bubbles.
## Eimac sez that forced air is good for 50 w per sq cm of anode area. And
135 W
for vapour phase cooling. Water cooling is the best at 1000 w per sq cm.
## the ultimate setup is multiphase cooling..a combo of water-vapour- then
back to water
cooling. But that would be difficult to implement on a SS device.
## Plane water cooling would be the easiest to implement. Schemes using
freon would also work,
but as others have noted, then u have condensation problems..and ditto with
vapour phase cooling.
Jim VE7RF
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