And then there were those who immersed metal 6L6's and 1614's upside down in
a bucket of water and ran them at 100W out.
Carl
KM1H
----- Original Message -----
From: "Roger" <sub1@rogerhalstead.com>
To: "Carl" <km1h@jeremy.mv.com>
Cc: <TexasRF@aol.com>; <larry@w7iuv.com>; <amps@contesting.com>
Sent: Monday, April 05, 2010 3:26 PM
Subject: Re: [Amps] liquid cooling
>
>
> Carl wrote:
>> Sounds like a job for good old PCB transformer oil maybe???
>>
>
> Actually good old Dow Corning 200 fluid.
> There are no normal cooling fluids that have a greater thermal
> conductivity than water.
> I worked on a project with an engineer many decades ago trying to come up
> with a substitute fluid for a solar heating system that could be used in
> northern climates and not freeze at night. We had some pretty good stuff
> (basically 200 fluid of different viscosities), but it was expensive.
>
> As to those talking about tubes submerged in oil such as the rectifiers in
> X-ray machines, that is primarily for insulation
>
> 73
>
> Roger (K8RI)
>> Carl
>> KM1H
>>
>>
>> ----- Original Message -----
>> From: <TexasRF@aol.com>
>> To: <larry@w7iuv.com>; <amps@contesting.com>
>> Sent: Monday, April 05, 2010 12:15 PM
>> Subject: Re: [Amps] liquid cooling
>>
>>
>>
>>> Larry, I wonder why your aversion to using water?
>>>
>>> 73,
>>> Gerald K5GW
>>>
>>>
>>>
>>> In a message dated 4/5/2010 11:07:23 A.M. Central Daylight Time,
>>> larry@w7iuv.com writes:
>>>
>>> The recent discussion on water cooling amp tubes got me thinking.
>>> Again.
>>> (not a good thing)
>>>
>>> Basically I would like to play with liquid cooling but I can't/won't
>>> use
>>> water. While I was still working, I worked on a multi-kilowatt
>>> amplifier
>>> that was oil cooled. It went into the avionics bay of an aircraft where
>>> all the rest of the equipment was also oil cooled.
>>>
>>> As I recall, the oil looked and felt like mineral oil, but I'm sure the
>>> military wouldn't use something that common and cheap and low flash
>>> point. At the time, I pulled up the MSDS for the oil but no longer have
>>> it and of course I can't remember the numbers.
>>>
>>> K8CU talks about using ATF for cooling liquid here:
>>>
>>> http://www.realhamradio.com/liquid-cooling.htm
>>>
>>> Unfortunately, there is no indication in the article that he or anyone
>>> else actually used ATF. Now ATF contains sulphur compounds that eat
>>> silver plating and cannot normally be used in things like dummy loads
>>> because of this property. However, a set of heat exchangers used for
>>> tube cooling would not have that problem.
>>>
>>> K8CU also mentions mineral oil and says it is not suitable due to the
>>> low flash point. I have to wonder about that because for one I would
>>> hope nothing in a system I would build would ever get hot enough to
>>> worry about flash point and two, it probably won't flash anyway due it
>>> being in a closed system with little or no free air/oxygen.
>>>
>>> What I'm looking for is someone who has actually done liquid cooling
>>> with something other than water. No, I have no interest in "flat earth"
>>> theories, or what you think you remember from a thermodynamics class
>>> you
>>> sat through 40 years ago. I want actual test results and operational
>>> data from real world applications.
>>>
>>> 73, Larry
>>>
>>> Larry - W7IUV
>>> DN07dg - central WA
>>> http://w7iuv.com
>>> _______________________________________________
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>>> http://lists.contesting.com/mailman/listinfo/amps
>>>
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>>> http://lists.contesting.com/mailman/listinfo/amps
>>
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>>
>>
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