Mike and others, The Dallas Semiconductor "Nonvolatile Timekeeping RAM" found in many popular controllers, including the Link RLC-1 Plus, is Part Number DS1643-150. The 11-page datasheet can be downloaded here:
<www.datasheetarchive.com/pdf/1235806.pdf> Notice that the "-150" indicates 150 ns access time. The replacement device offered by Dallas/Maxim has either 70 ns or 100 ns access time, and I have no idea if the newer device will work properly where a 150 ns device was used. On page 5 of the datasheet is a paragraph entitled "Internal Battery Longevity" which states that the device can operate for 10 years in the absence of VCC power. When powered as it would normally be in a typical application, the note states that the lifetime can be as long as 20 years. The battery is not accessible for replacement. I see that the guaranteed accuracy of the DS1643 clock is within +/- 1 minute per month, and there is no capability to tweak the crystal to get better accuracy. One of the Hams in my area is experimenting with a scheme to use a so-called atomic clock to jam-set the correct time once per day. With regular synchronism to WWVB, the time announcements will normally be no more than a second off. Once he gets this idea working, perhaps I can get him to write an article about it. I and many other "time-and-frequency geeks" think that time announcements should be correct. 73, Eric Lemmon WB6FLY -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Mike Morris WA6ILQ Sent: Sunday, November 11, 2007 12:29 PM To: [email protected] Subject: Re: Re: [Repeater-Builder] RC-96 Controller Problem I don't have my Dallas Semi book handy, but if I remember correctly the "10 years" spec was 10 unpowered years - if the Smartwatch was in a device that was powered up the battery was not being drained. But you still had to factor in the shelf life of the internal coin cell. At 03:44 AM 11/10/07, you wrote: >Eric, > >As Kevin said if your 96 has one of the Dallas Smartwatch the >battery in some of them had a life of 10 years. It was basically >the shelf life of the battery. > >Most of the Smartwatch's I've seen used a RAM as the memory rather >than a EPROM. The battery maintained the memory when power was >lost. The battery could power and maintain memory for the life of >the battery which again was spec'd for 10 years although most often >lasted 12-14 years. Kinda gets into the area of some rigs having >their OS in battery backed RAM. > >The Smartwatch was made by Dallas Semiconductor. > >73, ron, n9ee/r > > > > > >From: "Kevin Berlen, K9HX" <[EMAIL PROTECTED] <mailto:k9hx%40arrl.net> > > >Date: 2007/11/10 Sat AM 02:42:39 CST > >To: [email protected] <mailto:Repeater-Builder%40yahoogroups.com> > >Subject: Re: [Repeater-Builder] RC-96 Controller Problem > > > > >What version of software is in your controller? With rev 5 of > thesoftware, a Dallas > >Smartwatch was added to the RC-96 to provide a real-time clock. As > Irecall, the > >smartwatch occupied one of the eprom sockets, and the affected > eprom wasplugged > >into a socket on top of the device. If yours has the smartwatch, > it maybe the culprit. 73. > > > >Kevin, K9HX > > > > > >At 10:10 PM 11/9/2007, you wrote: > > > >One of the repeaters I maintainhas been working perfectly for almost a year > >since its last checkup. It is a 6m repeater that has a link toseveral > >other 6m repeaters, and is controlled by an ACC RC-96 controller. Itis > >powered from a very large commercial UPS that ensures no-breakpower. > > > >One evening, the controller went berserk, for no apparent reason. It > >started transmitting a string of Morse characters on both the primaryand > >secondary ports: "dit dah dit ... dah dah dah dah dah dah dah dahdah dah > >..." for about two minutes. It would then be quiet on both ports forabout > >30 seconds, and would then repeat. During the brief silent periods,the > >repeater would operate as a repeater, but the Morse string muted anyother > >audio, once it began. The controller would not respond to my DTMFcommands > >on either the primary or secondary ports. To make matters worse, the > >telephone line that gives me backup control to knock down the repeaterwas > >dead at the hilltop end! I had to make a hasty trip to the mountaintopsite > >to take the beast off the air. > > > >As a result of this experience, I am adding a dedicated UHF control linkto > >give me positive control of the repeater. > > > >Has anyone else had a similar problem with the RC-96 controller? Notethat > >there is no lithium or similar memory battery inside the box that mightgo > >bad. Oddball malfunctions like this can add more gray hairs than Iwant! > >Any ideas, case histories, or suggestions will be appreciated. > > > >73, Eric Lemmon WB6FLY > > > > > > > >No virus found in this incoming message. > >Checked by AVG Free Edition. > >Version: 7.5.503 / Virus Database: 269.15.26/1119 - Release > Date:11/8/2007 5:55 PM > > > > > > > > > >No virus found in this outgoing message. > >Checked by AVG Free Edition. > >Version: 7.5.503 / Virus Database: 269.15.27/1121 - Release Date: > 11/9/2007 7:29 PM > > >Ron Wright, N9EE >727-376-6575 >MICRO COMPUTER CONCEPTS >Owner 146.64 repeater Tampa Bay, FL >No tone, all are welcome. > > > > > > > >Yahoo! Groups Links > > >
