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- Newsgroups: sci.electronics
- Path: sparky!uunet!elroy.jpl.nasa.gov!usc!newshub.sdsu.edu!chemteca.sdsu.edu!massoud
- From: massoud@chemteca.sdsu.edu (Massoud Ajami)
- Subject: Re: Cable, Stereo, and VCR Questions [correction]
- Message-ID: <massoud.21@chemteca.sdsu.edu>
- Keywords: Cable TV Stereo VCR
- Sender: news@newshub.sdsu.edu
- Nntp-Posting-Host: 130.191.227.22
- Organization: San Diego State University
- References: <1992Jul27.133817.11872@lonex.rl.af.mil> <massoud.20@chemteca.sdsu.edu>
- Distribution: usa
- Date: Wed, 29 Jul 1992 15:01:21 GMT
- Lines: 52
-
- In article <massoud.20@chemteca.sdsu.edu> massoud@chemteca.sdsu.edu (Massoud Ajami) writes:
-
- >In article <1992Jul27.133817.11872@lonex.rl.af.mil> Brian R. O'Hern (BRO'Hern) writes:
-
-
- >> I have three questions:
-
- >>1. I have a lot of RG-58C (50 ohms) and was thinking of using it to
- >>connect my Marantz 200W amp to a pair of Klipsh Heresy speakers.
- >>Are my calculations showing that nearly 86% of the signal would be
- >>reflected back from the 8 ohm load? So, not only "no" but "hell no"
- >>I shouldn't use coax to drive my speakers?
- >> However, my instinctive feelings tell me that at because the line
- >>is not infinite (transmission line theory), the connection is
- >>analyzed as a RC circuit showing the characteristic impedence of the
- >>line is close to the load value so reflection isn't a problem. Also,
- >>at 30pF a foot, an audio signal would hardly notice. In fact, it
- >>seems connections using coax would be better than a zipcord (~150
- >>ohms) or even a twisted pair and much less noisy than both?
-
- >>1a. Side Ques: I heard that the "Heresy" name came about because its
- >>design (Conventional paper cone) is not the standard (does not
- >>follow the Klipsh design doctrine). Any truth to this?
-
- >>2. Is there a FAQ list on VCR problems? It seems that everyday there
- >>is at least one question about VCRs... speaking of which... I have
- >>a RCA that stops a couple seconds after pushing play no matter where
- >>you are on the tape.
-
- >>3. I have a couple of coax splitters that I acquired in college from
- >>my cable connection. I would like to use them to split an antenna
- >>signal (one to TV one to FM stereo). Is there any truth to the
- >>rumor that the splitters filter out high UHF? I.E. I won't get
- >>channel 68 (~795MHz) through it.
-
- >>Thank you for any comments.
-
-
- >>BRO'HERN
- >>STD DISCLAIM APPLIES ('disClaim dat I make is no lie...)
- >>This medium is subject to monitoring. Use of this medium constitutes
- >>consent to such monitoring.
-
- >If the length of your speaker wire was longer than 2.5 kilometer, then
- >you can use transmission line theory. 2 E8(signal velocity)/20kHz.=10000
- >meter. Rule: if the propagation delay was [less] more than 1/4 of rise time
- ^^^^^^
- >of the signal (@ max. frequency), then the medium acts as a transmission
- >line.
-
- >3- Some cheap splitters do the filtering by means of higher insertion loss
- >at higher frequencies, but still you can get ch. 68.
-