Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!caip!topaz!husc6!seismo!umcp-cs!chris From: chris@umcp-cs.UUCP (Chris Torek) Newsgroups: net.audio,net.analog Subject: Re: need interconnect cable recommendations... Message-ID: <2419@umcp-cs.UUCP> Date: Mon, 14-Jul-86 22:19:27 EDT Article-I.D.: umcp-cs.2419 Posted: Mon Jul 14 22:19:27 1986 Date-Received: Tue, 15-Jul-86 05:32:33 EDT References: <2107@orca.UUCP> <926@ihu1g.UUCP> <1225@uwmcsd1.UUCP> <476@copper.UUCP> Reply-To: chris@maryland.UUCP (Chris Torek) Distribution: na Organization: University of Maryland, Dept. of Computer Sci. Lines: 39 Xref: watmath net.audio:8975 net.analog:944 In article <476@copper.UUCP> michaelk@copper.UUCP (Michael Kersenbrock) writes: > Skin effect is why RG-59 can be made with a copper- > plated iron conductor. RG-59 is primarily sold as TV cable (at RS) > where the lowest frequency (channel 2) in the cable is over 50 Mhz > (and channel 83 is MUCH higher). Ch. 2 ranges between 54 and 60 MHz; 83, between 884 and 890 MHz, according to the _Handbook of Electronic Tables and Formulas_ (for some reason I have a copy of this book). Incidentally, each TV channel is 6 MHz wide; 2 starts at 54 MHz, and there are jumps at channels 5 (76-82 MHz), 7 (174-180 MHz), and 14 (470-476 Mhz). (This is what comes of not providing for expansion!) >3) If you would like a lower-capacitance interconnect you might try > RG-62 that has a mostly-air dielectric. Depending where you get > it, it costs little more than RG-59 which is about the same size . The _Handbook_ also lists the properties of a number of RG-*/U cables: Cap Attn dB per 100 ft Type Imp (pF Dia 1 10 100 400 1000 RG.../U (ohms) per ft)(inches) MHz MHz MHz MHz MHz Remarks ------- ---- ---- ------ ---- ---- ---- ---- ---- -------- 59 73 21 .242 .30 1.1 3.8 8.5 14.0 TV lead-in 62 93 13.5 .242 .25 .83 2.7 5.6 9.0 Low capacity, small RG-63U is higher impedance, and thicker, but has less loss at higher frequencies, and a lower capacitance: 63 125 10 .405 .19 .61 2.0 4.0 6.3 Low capacity There are others with even lower high-frequency losses listed, RG-117U being the lowest, though more capacitive than any of the ones above. Oh well, enough esoterica: the _Handbook_ has plenty. -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 1516) UUCP: seismo!umcp-cs!chris CSNet: chris@umcp-cs ARPA: chris@mimsy.umd.edu