Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!cornell!uw-beaver!tektronix!midas!jeffw From: jeffw@midas.TEK.COM (Jeff Winslow) Newsgroups: sci.electronics Subject: Re: need help to reduce a monitor's squeal Message-ID: <3459@midas.TEK.COM> Date: 28 Sep 88 16:32:46 GMT References: <716@pedsga.UUCP> Reply-To: jeffw@midas.UUCP (Jeff Winslow) Organization: Tektronix, Inc., Beaverton, OR. Lines: 22 In article <716@pedsga.UUCP> jeffj@pedsga.UUCP writes: >I can hear several terminals and televisions 'squeal'. >I understand that this is the flyback transformer at the scan frequency. True. Sometimes, however, you're hearing instability in the switching power supply often used in these units. This happens more often than you might think, even with supposedly "perfected" and "professional" designs. These noises are almost always pitched lower and are (to me) much more irritating that the scan frequency. >Is there anything I can do to attentuate the squeal? When my terminal squeals, I drop its back end on the desk from about 1/2" up. Most of the time it quits, so I suspect the transformer mounting is a bit, ah, flexible. Funny thing - I just tried it out and it caused the noise to *start*. I had to drop the front from about an inch up - twice - to get it to stop. Isn't this fascinating? :-) Jeff Winslow