It also uses less copper so the costs are less, important when lines are measured in miles not feet!
Robert. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Poul-Henning Kamp Sent: 10 May 2007 21:53 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 50 vs 75 ohm cables In message <[EMAIL PROTECTED]>, John Day writes: >So 75 ohms as we >know it now is a compromise between the low attenuation 77 ohms and >the 73 ohm dipole feed-point. I can confirm that the choice of 75 Ohm for telecom use indeed is because of the low attenuation. The first use of coax was for "Carrier Frequency" systems, where a number of telephone conversations were AM modulated on individual carriers, usually 4 kHz apart. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts -------------------------------------------------------- Genetix Limited - Queensway, New Milton, Hampshire, BH25 5NN Registered in England No. 2660050 www.genetix.com Any opinions expressed in this email are those of the individual and not necessarily Genetix Ltd (Genetix) or any company associated with it. This email and any files transmitted with it are confidential and solely for the use of the intended recipient. If you are not the intended recipient or the person responsible for delivering to the intended recipient, be advised that you have received this email in error and that any use is strictly prohibited. If you have received this email in error please notify Genetix by telephone on +44 (0)1425 624600. The unauthorised use, disclosure, copying or alteration of this message is strictly forbidden. This mail and any attachments have been scanned for viruses prior to leaving Genetix network. Genetix will not be liable for direct, special, indirect or consequential damages as a result of any virus being passed on, or arising from alteration of the contents of this message by a third party. -------------------------------------------------------- _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
