Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site watdcsu.UUCP Path: utzoo!watmath!watdcsu!herbie From: herbie@watdcsu.UUCP (Herb Chong [DCS]) Newsgroups: net.audio Subject: Re: Copy protected records? Message-ID: <944@watdcsu.UUCP> Date: Mon, 11-Feb-85 14:51:27 EST Article-I.D.: watdcsu.944 Posted: Mon Feb 11 14:51:27 1985 Date-Received: Tue, 12-Feb-85 04:50:49 EST References: <305@boulder.UUCP> Reply-To: herbie@watdcsu.UUCP (Herb Chong [DCS]) Distribution: net Organization: U of Waterloo Lines: 32 Summary: In article <305@boulder.UUCP> jon@boulder.UUCP (Jonathan Corbet) writes: >[] > > I have heard rumors from a couple of sources now that some record >companies are adding a high frequency signal to their records that >interfere with the bias on tape decks, thus making it difficult to make >tapes of said records. Does anybody know if this is really true, and >if so, just what the technique is? > >-- >Jonathan Corbet >National Center for Atmospheric Research, Field Observing Facility >{seismo|hplabs}!hao!boulder!jon i think that this rumor is false. most cartridges do not have enough high frequency response to deliver such a signal at a sufficient level to affect taping by overbiasing. remember that about the minimum acceptable frequency for bias is about 90kHz. if the signal was sufficiently high in level to be reasonably reproduced by the majority of cartridges, almost all would not be a able to track it. also, most cutter heads do not reproduce past about 35kHz. the CD-4 records that required response to 50kHz were all half-speed mastered to get around this problem. Herb Chong... I'm user-friendly -- I don't byte, I nybble.... UUCP: {decvax|utzoo|ihnp4|allegra|clyde}!watmath!water!watdcsu!herbie CSNET: herbie%watdcsu@waterloo.csnet ARPA: herbie%watdcsu%waterloo.csnet@csnet-relay.arpa NETNORTH, BITNET, EARN: herbie@watdcs, herbie@watdcsu