[Amps] SS amps watercooling - was PowerGenius XL

[Jim Thomson]

Date: Tue, 21 Feb 2017 20:11:08 -0500
From: "Roger (K8RI)" <k8ri at rogerhalstead.com>
To: amps at contesting.com
Subject: Re: [Amps] SS amps watercooling - was PowerGenius XL

Not sure what you are disagreeing with.  Distilled water presents a high 
resistance when first used, BUT, distilled and de-ionized water is ion 
hungry, or rephrased, quite corrosive. It will take the strength out of 
brass fittings to the point where you can crumble them between your 
finger.. IE, hose barbs. It is the metal ions that increase the 
conductivity. Tap water (with no salt) is still conductive)

As the water ages, the dissolved metal ions lower the resistivity. 
That's why we monitor the resistivity. Eventually the resistivity gets 
low enough that the water needs to be replaced with, fresh, clean, 
distilled water.

73, Roger (K8RI)

##  distilled water is water that has been boiled, and the steam
condensed back to water.  Its pure water.  AFAIK,  distilled 
water is not ion depleted.   If it is ion depleted, bad news, it will
eat the insides out of any external rad used....esp Aluminum. 

##  de-ionized water is a chemical process, so you end up with pure
water..... without having to go through the boiling process.  

##  You cant use 100 % distilled water in any eng or supercharger closed loop
system, unless corrosion and rust inhibitors are used.   100%  distilled water
extracts a lot more heat vs  a 50-50 mix of distilled water + glycol. 

##  so dunno if distilled water would work in a SS application.  Do you really require
the high resistivity  for a 50 vdc  device ?   I thought there was an electrical insulating
barrier between the LDMOS and its mating heatsink.   If so, water resistivity is 
a moot point. 

## Plane jane tap water is used for water cooled dummy loads.  20 kw into 50
ohms =  1414  V peak.  Those type of dummy loads are not an issue.  Available
up to 200 kw. 

Jim   VE7RF