Path: utzoo!utgpu!watmath!uunet!lll-winken!pacbell!att!icus!limbic!gil From: gil@limbic.UUCP (Gil Kloepfer Jr.) Newsgroups: unix-pc.general Subject: Re: Keyboard Cables? / external disk RF signal Summary: Ugh Message-ID: <461@limbic.UUCP> Date: 13 Feb 89 06:22:05 GMT References: <7454@ihlpf.ATT.COM> <1542@lznv.ATT.COM> <112@gnosys.UUCP> <432@limbic.UUCP> <116@gnosys.UUCP> Reply-To: gil@limbic.UUCP (Gil Kloepfer Jr.) Distribution: unix-pc Organization: ICUS Software Systems, Islip, NY Lines: 43 In article <116@gnosys.UUCP> gst@gnosys.UUCP (Gary S. Trujillo) writes: >Hey, Gil - I meant that as a JOKE! :-) (Guess you missed the smiley, >or thought it applied only to the part about the periscope. Oh well. >Still, I appreciate the effort you put into giving the idea some thought. Guess so. It really WAS a neat idea though ;-) [RF and 2nd disk upgrades] >He says that once you start running external cables around that whole situation >can change very drastically. Have you given any thought to that problem? Have >you measured RF radiation, even by means of noting the effect of the external >cable on nearby radio and television receivers? Same question to jbm. >Gary S. Trujillo {linus,bbn,m2c}!spdcc!gnosys!gst >Somerville, Massachusetts {icus,ima,stech,wjh12}!gnosys!gst Ugh... I've already read John Milton's reply, and my position on it stands equally with his. In the hard disk upgrade instructions I'm distributing, I mention briefly the problems with RF interference. In that brief section, I discuss how BIG of a problem it is. I disagree with John on one point: I don't think shielding the cables will solve the problem completely, or even sufficiently. I've had a homemade expansion board INSIDE my machine for a while, buffering SOME address/data lines and sending them out through a ribbon cable wrapped in aluminum duct tape. The TV interference improvement was negligable. I think in order to keep the interference down completely, you will need to shield ALL parts of the upgrade, including the PC/perf-board. My guess is that the board would have to be put inside a shielded metal box. What further baffles me is that there are not constantly signals going to/from the hard disk. Why is there constant interference on a TV? I suspect that the cables are leaking other-than-disk signals outside the shielded cabinet. (see below) A "someone" who wishes to remain anonymous and who currently has the second hard disk upgrade in his 3B1 will get thrown out of the house by his family soon when they find that channels 2 (CBS) and 4 (NBC) on their portable TV don't come-in anymore because of a certain external hard disk. Sigh... ------- Gil Kloepfer, Jr. U-Net: {decuac,boulder,talcott,sbcs}!icus!limbic!gil ICUS Software Systems Voice: (516) 968-6860 [H] (516) 746-2350 x219 [W] P.O. Box 1 Internet: gil@icus.islp.ny.us Islip Terrace, NY 11752 "Life's a ... well, you know..."