[Amps] Liquid Cooling

[John Lyles]

At work we use oil cooling for a number of situations with high voltage. The oil gives a great benefit for insulation and allows more compact layouts. I don't know of any RF amplifiers this way, only pulse amplifiers using planar triodes and thyratrons. 
The tube is basically sitting under the oil. However, I have not worked on any of these designs, and I believe they still require some mechanical work to force the oil to carry the heat by the anode. In one system there is a small recirculating oil pump and 
pipes, all immersed. (not the pump motor). The oil is typically a silicone-based liquid called Envirotemp 200.  You can also used Envirotemp FR3. You can also just use transformer oil, like Shell Diala. 
John 
K5PRO




> 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.
...
> 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