Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!bellcore!texbell!vector!telecom-gateway From: wmartin@st-louis-emh2.army.mil (Will Martin -- AMXAL-RI) Newsgroups: comp.dcom.telecom Subject: Re: Radio Time Sources Message-ID: Date: 22 May 89 14:03:24 GMT Sender: news@vector.Dallas.TX.US Lines: 40 Approved: telecom-request@vector.dallas.tx.us X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@vector.dallas.tx.us X-TELECOM-Digest: volume 9, issue 174, message 3 of 4 Several postings to the list have pointed the original inquirer to the Heathkit "Most Accurate Clock" as something that would fill his requirements for an off-the-air source for, as he put it, "reliable standard time for a LAN". [I just went to look this up so I could post the model and be sure I got the facts right, and it seems that my Heathkit catalog here at work has walked off the shelf... Grrr...] It may purport to provide that service, but I would like to point out that reviews of that clock that appeared on the Info-Hams list some years back really panned it. It was most definitely NOT "reliable". The main problem seemed to be that the shortwave-receiving section, which was supposed to automatically tune the best signal from WWV on 2.5, 5, 10, or 15 MHz (don't recall if it tuned 20 MHz) was not very good, and often lost all trackable signals on any frequency. When it did that, it was supposed to switch over to its internal clock and then sync back up when it could receive a trackable WWV signal again. Well, the internal clock was inaccurate! That seems incredible in these days of $5 drugstore watches that keep better time than the finest mechanical movements did a few decades ago, but it seemed to be the case. More than one owner of this clock reported that as a problem to the net. Maybe Heath has improved this model since that time, but I would be VERY wary of putting my trust in it, and slaving automated system-time-setters to this device. There are commercial firms that sell far-more-expensive versions of this sort of time standard, and you really so seem to get what you pay for in this area. The more expensive sets tune the VLF WWVB signals, not the shortwave, so as to avoid the vagaries of shortwave propagation. You might luck out and get a Heath model that works fine, or be skilled enough to tinker with it and tweak it to better performance, but, if you are spending your company's money and not your own, I would recommend going with a professional piece of equipment. As I recall, the bad reviews were not only on the net, but also Radio Canada International's SWL Digest program, which has monthly receiver reviews by Larry Magne, reported these problems also. Regards, Will Martin