authorplaceholder@datacube.UUCP (07/16/86)
The biggest problem with using aluminum shielded coax for low frequencies is the shield resistance. High ground resistance causes signal losses and crummy grounding. At RF, skin effect takes over, so aluminum is OK. Same with the center conductor. Iron is fine for RF, not for audio and video. Don't worry about wire impedance until you reach a frequency or wire length where the wire length is greater than about 1/10 wave. Thus audio at a frequency of 20KHz, the wavelength is 15,000 meters, so mismatched wire over 1500 meters will begin to give reflection problems for audio. As far as skin effect, I believe that it only cuts in above 1MHz. Dave Erickson ------------------------- Datacube Inc. 4 Dearborn Rd. Peabody, Ma 01960 617-535-6644 ihnp4!datacube!dje mit-eddie!mirror!datacube!dje