CompuServe Messages

You should not remove safety grounds from equipment, it's unsafe for the operator, in some cases it can increase the equipment's susceptibility to R.F. and it's illegal (the SGP [safety ground police] are everywhere!) I think Newtek offered a way of trouble shooting and identifing the source of the interference, not a solution to it. The "ideal" audio system ground would be a "star" or single point ground system where each piece's analog signal ground goes to a centrally located copper plate (insulated from any other ground) which in turn has one wire to the AC ground (waterpipe). Then each of the chassis grounds (safety ground) goes to the AC outlet. All input and output cable shield's are left floating (disconnected) at the receiving end. (I'm not so sure about applying this floating shield idea to higher frequency video signals and I'm not to crazy about hackin-up all my cables) Those of us who don't have equipment with a "floating" (seperate from the chassis) analog signal ground, must rely on the third wire safety ground connected to one isolated ground recepticle (seperate ground wire to AC ground/waterpipe). This, I believe, is the way Jerry hooked up his system (chassis ground wires, in a "star" configuration, to one outlet – then to the ground rod). All this talk about ground loops had me searching thru stacks of stuff to find my secret SGP file on grounding – (access on a need to know basis only!)… I found it! So for anyone that's interested here's a list of info sources: A CLEAN AUDIO INSTALLATION GUIDE, by A. Burdick,Benchmark Media Sys. Inc. 5925 Court St. Rd., Syracuse, NY 13206 WIRING AN AUDIO-VIDEO PROD. FACILITY, by E.Howard, Broadcast Eng.Mag. 9/86 GROUNDING AFFECTS NOISE & SAFETY, Sound Info Series data sheets by Yamaha Corp, PO 6600, Buena Park, CA 90622 WHAT'S ALL THIS GROUND NOISE STUFF, ANYHOW?, by B.Pease, Electronic Design Mag., 6/24/93, pg.70 ELIMINATING NOISE: A HUM-BLE LIMERICK, by Peter Utz, AV Video Mag, 6/92 North Hills Elec. Inc. (516-671-5700) offers several video isolation transformers which can be used to eliminate ground loop problems. Isolation transformers work if you know the source of the problem. I used a home made one to solve my cable TV gremlin. Smac @;-^D 70714,1567 ICA service Inc.