Maybe it's just me, but I've never understood the need for a special circuit to run cooling fans.
I run my fans from the PTT line using a relay. I have also used a simple chassis thermostat, but prefer using PTT. I suppose you could easily use both methods so that in the event that the equipment remained too warm when PTT halts, the thermostat could keep it running longer. However, I contend that if this is happening, your fans are inadequate and not keeping up with the demand right along. Why the need to continue cooling after the QSO has ended? Just because you can? Chuck WB2EDV ----- Original Message ----- From: "skipp025" <skipp...@yahoo.com> To: <Repeater-Builder@yahoogroups.com> Sent: Sunday, December 21, 2008 12:24 PM Subject: [Repeater-Builder] Re: fan timer circuit > Re: fan timer circuit > > I've seen a number of fan delay, time on, time off circuits > posted on web. The "neat'o web page" url I just posted here > on the group has one and it might be the one you're looking > for. > > http://www.w1ghz.org/small_proj/small_proj.htm > > .... and the fan controller information is about half way > down the page with a picture and down-loadable zip file. > > My own personal preference is to run everything warm and even > a lot higher temp than most of you would expect. In a repeater > station operation only an RF PA and un-modified Astron Power > Supply with an undersized heat sink might get a fan. Never a > failure of a well planned installation. > > Some of our local "start-up" radio clubs throwing repeater > packages in place often start out using and stay with an > external RF amplifier designed for mobile operation. Sometimes > the amp runs so hot you can't keep your hand on the heat sink > but I've yet to see one fail. > > > cheers, > skipp >
