[Amps] WATER for vapor cooled amplifier

[Dan Elyea]

My place of work is an HF transmitting facility.  We have a number of
100 kW transmitters using the vapor phase cooling approach.

Back in 1977, when we brought the first one on the air, we were having a
problem locating distilled water within reasonable driving distance.
Distilled water is the recommendation from the manual. (Each transmitter
requires about 75 gallons.)  After consulting with one of the
manufacturer's engineers, we filled up with deionized water (which was
readily available).  The resistivity was very low---totally unsuitable
to hold off the HV.  (Perhaps "de-ionized" water comes in several
varieties of quality.)  Anyway, it appeared to be bad advice.

We had to drive the long distance to get the distilled water, and flush
the system out to get the resistivity readings that were acceptable.

We now use Zephyrhills distilled water, and find it completely
satisfactory in terms of resistivity and holding off 12 kV of HV.

73, Dan  K8YKO



> Message: 1
> Date: Tue, 6 Feb 2007 10:03:08 -0700
> From: "John T. M. Lyles" <jtml at lanl.gov>
> Subject: [Amps] WATER for vapor cooled amplifier           TSPA
> To: amps at contesting.com
> Message-ID: <p06230900c1ee62483339@[128.165.34.51]>
> Content-Type: text/plain; charset="us-ascii" ; format="flowed"
> 
> Paul
> Deionized water is what you have to use for high resistivity water.
> Distilled is not acceptable as the ionic content is now low enough.
.