[Amps] WATER for vapor cooled amplifier

[Paul Christensen]

> "Okay, so let's back up one step and sorta tabulate our findings
> and observations..."

A significant difference in the use of water with RF loads is that it is not 
mixed with high-voltage and accordingly, probably no real reason to minimize 
leakage, but immunity to long-term corrosion is important.  Typically, in a 
water-cooled load, water flows through a glass jacket which, surrounds a 
50-ohm resistive element.

In my prior life, I used a 25KW Altronic water-cooled load on a Harris 
FM-20K commercial broadcast transmitter.  We simply ran a hose from the 46th 
floor water tap and it remained that way for 15+ years without encountering 
any trouble.  In all fairness though, I believe the building (downtown 
office complex) used a soft water system.

On the other hand, since the vapor-cooled amps require good HV isolation, it 
would seem that the water requirements are much more restrictive with two 
overarching requirements: (i) low water conductivity; and (ii) low corrosive 
action.  I am not sure what the right answer is but the Zephyhills product 
labeled as "distilled" seems to work well with my Alpha 70V.

Paul, W9AC