At 11:02 PM 3/19/05, you wrote: >Hi Yall >I missed the beginning of the thread on the 12 volt fans would someone >clue me in on filtering. > >Thanks .....bob
It started on 3/18 with message 38409 from kc4wgh Check the archives at <http://groups.yahoo.com/group/Repeater-Builder/messages/48509> The thread boiled down to, in my opinion, that in an AC environment, you want to use AC fans. In an environment where the system is going to run on DC (i.e. battery backup) you need to run a good LC filter on the fans as many electronic commutator fans will feed trash back on the power feed, and if there is not enough filtering the trash will get into the system audio. Personally I have an old dirty fan (electrically dirty) that I use for testing... It's a no-name 120mm size with the only identifier "Made in China". I put that fan on the RX +12 power feed and see if it affects the RX audio. If it does, I fix the filtering in the RX, not the fan ! Likewise I put it on the TX +12 power feed and see if it affects the TX audio. If it does, again I fix the filtering! If the power filtering in the RX or the TX is marginal, I want to know BEFORE the new box goes up, perhaps at a site that I can't get to from first snowfall to last snowmelt (which may be anywhere from mid-march to late april). Mike WA6ILQ 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/
