Actually, yes.. this may be difficult to describe.. but here goes. We took a solid-state amplifier used for a 2.4GHz ATV repeater, and wound copper tubing through the existing cooling fins of the heatsink material. The copper tubing was just the correct size to make a firm "press-fit" between the fins for the heat exchanger portion. Then the the amp fins are oriented horizonally with the input at the bottom. The resivoir was above the amplifier. As the glycol mix is heated it begins to rise through the cooling fins (within the tubing) to the resivoir. And as it cools in the resivoir, it falls toward the input to the heat exchanger on the fin assembly. Nice convection driven system, not dependant on a pump (so no current drain for battery/solar systems!!).
Originally it did have a pump, but we discovered, quite by chance, when the pump failed... that it wasn't needed due to the placement of the resivoir. I would send pix, but the system was torn down a few years ago. And we didn't document things as we should have. We all know how poor the effeciency of solid state amplifiers is at these freqs... so this thing generated a ton of heat!! Users would bring the repeater up and run for hours... using the 900MHz twin/1200MHz sister systems to make a full-dux connection. Teaching classes... or just putzin' around. But using this sytem, it ran very cool to the touch. You could probably make it much more efficient by using on of the aftermarket oil/transmission fluid coolers placed in a "laying flat" position with a small fan or two... but we never found that to be necessary. All three bands of the system were configured identically. Who knows... it may work for others as well... The most difficult part of this system, was sleeping at night knowing there was a fluid reservoir at the top of the rack, above all that expensive gear!! As I said, it was in service for a number of years, and still would be if folks hadn't lost interest in ATV in our area... YMMV... mike -----Original Message----- From: Tony King, W4ZT [mailto:[EMAIL PROTECTED] Sent: Monday, April 11, 2005 11:54 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: Need Kenwood TK-780 repeater controller hookup That's an interesting device for a computer but I wonder why anyone would go to all that trouble (except for fun of course) when you can easily cool a Mastr II continuous duty PA with the same number of fans and it'll run cool and comfortable forever. For the price you'd pay for that water cooling unit ($200 class) you can buy the Mastr II PA and the new fans. It'll keep running even if the fans die. That's reliability which is what you want if you're putting up a repeater. 73, Tony W4ZT Dave VanHorn wrote: > > >>Power would have to be reduced in lock to talk >>(repeater) applications and a decent small blower >>across the tx radio >> >> > > >I was cruising through fry's yesterday, and I wondered.... >Has anyone ever liquid-cooled a repeater? > >The Koolance Exos system looks pretty easy to apply, the only hard >part would be adapting an existing amplifier to use their waterblock. > >I have a Koolance machine here, that has run with ZERO failures in three years. >For me, that's very unusual. My machines tend to run heavily loaded, >and run 24/7, so I normally expect an HD, motherboard, CPU, or power >supply failure every 3-6 months. > >The new Koolance HD cooler looks like you could apply it against an >amplifier pretty easily. >The old one used thermally conductive "goop" that you poured all over >the electronics in your HD, then put the cooler block onto. >This is how the two drives in this machine are done, they run so cool >you'd never think they are on. > >A key element of course, would be a 12VDC pump, which this unit apparently has. ><http://www.xoxide.com/koalex.html> > > Yahoo! Groups Links Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
