glycol and anti freeze. Sent from my iPad
> On Jul 23, 2020, at 4:49 PM, N2TK via Elecraft <elecraft@mailman.qth.net> > wrote: > > Hi Paul, > I can't remember what we used to use for closed loop cooling. I don't think > we used distilled water because it's resistance would increase over time from > picking up ions from the metal. In our case it was cooling loops in a copper > 37" electrode. I thought it was some kind of antifreeze or maybe an oil? And > also isn't distilled water quite reactive? > To many bourbons ago 😊 > N2TK, Tony > > > -----Original Message----- > From: elecraft-boun...@mailman.qth.net <elecraft-boun...@mailman.qth.net> On > Behalf Of Paul Christensen > Sent: Thursday, July 23, 2020 3:54 PM > To: elecraft@mailman.qth.net > Subject: [Elecraft] KPA1500 Cooling > >> "Until it leaks on the LDMOS devices." > > Pure water is an insulator. Leakage becomes a problem when water becomes > contaminated with conductive particles. This rarely occurs in closed loop > systems that use distilled water when non-contaminating hoses, fittings, and > heat exchangers are used. My 2KW LDMOS amp uses water cooling in such a > closed system. > > My main amplifier at home is an Alpha PA-70V. The amp uses an openly-cooled > vapor-phase system. A pint of distilled water separates 4KV of plate voltage > and chassis ground. Water is in direct contact with the plate. In time, air > particles do contaminate the water (usually in the form of algae) and the > system must be purged and refilled at annual intervals. If leakage exceeds a > predetermined amount, the amp faults and shuts down. > > Paul, W9AC > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html Message > delivered to tony....@verizon.net > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to w...@w2xj.net ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
