[Amps] Water cooling heat exchanger approaches

[Skram, Helge (MED)]

The water is in direct contact with the 7289's.
The original air cooler radiator has been removed and replaced by water
cooler jacket.
This screwed directly onto the anode. There is a input and a output tube for
water.
Are using plastic hoses to a automotive heat exchanger, water pump and a
water resevoir.
There is no RF on the anodes, since this is an cavity amplifier. The anode
is on the outside of the cavity.
There is only DC potential on the anode. The water should be deionized.

It is not a good idea to have different metals in the cooling system, but it
seems unavoidable by using the heat exchanger. Corrosion is axellerated by
increased temperatures and maybe also by the DC voltage. 
The water is contaminated over time and must be replaced at 2-6months
intervals.

In the beginning there was some white sluggish stuff in the water, that I
decided must have come from the plastic material in the water reservoir.
This could have been release of softener from the PVC water reservoir tube.
It was not corrosion products, because these are more like white powder.

The system has worked fine in about 1 1/2 years now.

73 de LA6MV
Helge


-----Original Message-----
From: Paul Christensen, Esq. [mailto:w9ac at arrl.net]
Sent: 29. oktober 2003 14:30
To: Skram, Helge (MED); Dfmich at aol.com; vhf at w6yx.stanford.edu;
amps at contesting.com
Subject: Re: [Amps] Water cooling heat exchanger approaches


In what context are you using water cooling with the 7289s?  Is the anode
directly in contact with water (with distilled water) or is an insulated
water jacket used?  If it is the former, then it is important to use a
radiator, condenser or exchanger which does not contaminate the water in any
manner.

Many automotive and industrial exchanger and radiators are assembled using
acid-core solder as opposed to the more preferable soft (rosin core) solder
which will not appreciably contaminate the water supply.

-Paul, W9AC

----- Original Message ----- 
From: "Skram, Helge (MED)" <helge.skram at med.ge.com>
To: <Dfmich at aol.com>; <vhf at w6yx.stanford.edu>; <amps at contesting.com>
Sent: Tuesday, October 28, 2003 4:18 AM
Subject: RE: [Amps] Water cooling heat exchanger approaches


> Hi
>
> I have a 23cm 2x 7289 amp from VE1ALQ using water cooling.
> Yes I came into the same situation, where do you get a "small transmission
> oil cooler".
> Couldn't find any, but then came to think that the heat exchanger in a
small
> car could be used.
> That is the small radiator heating the passenger compartment. I am not
shure
> what you call it.
> This was much easier to locate. Browsed the catalog of a local dealer of
car
> parts and found that
> the heat radiator for a Opel Corsa would fit perfectly. It was not too
> expensive at about $100.
> One advantage with this is that it is intended for water, which is not a
oil
> cooler.
>
> 73 de LA6MV
> Helge
>
> -----Original Message-----
> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com]On
> Behalf Of Dfmich at aol.com
> Sent: 28. oktober 2003 02:52
> To: vhf at w6yx.stanford.edu; amps at contesting.com
> Subject: [Amps] Water cooling heat exchanger approaches
>
>
> Hi there
>
> I am working on the water cooling apparatus for a N6CA 1/4 KW 23 cm amp.
In
> his article, he talks of using a "small transmission oil cooler" for the
> heat
> exchanging function. Does anyone that has done this before have any more
> specific descriptions than this; ie, a cooler from a 19xx Ford whatever or
> ......
> Are there any other sorts of approaches to this heat exchanging function,
> even
> homebrew ones?
>
> Thanks
> Dan K9EA
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps