Hi Bob, This may or may not apply, but "chip capacitors",?also known as?MLC (multi-layer ceramic) capacitors,?can fail from stress cracking?if?unevenly heated during the soldering process.?For this reason MLC?manufacturers advise against?hand soldering as the?fractures can be hard to see -- and the?failure can show up?weeks or months later.
73, Bob, WA9FBO S-COM, LLC -----Original Message----- From: [email protected] To: [email protected] Sent: Fri, 27 Mar 2009 9:17 am Subject: Re: [Repeater-Builder] Anyone ever used this repeater controller? At 3/27/2009 07:36, you wrote: >Bob, I've been considering getting one of the NHRC controllers for a GE >MVP. Are they dependable, or like your email mentions, having some >occasional failures? IMO, no. Our NHRC-micro has failed 3 times. The first time NHRC was nice enough to repair it under warranty, but the 2nd time they stopped answering e-mails, so I fixed it myself as well as the 3rd time a couple of months ago. Each time the problem was a bad chip capacitor. On the last failure the chip cap shorted the V+ line, vaporizing a trace as well as some of the board material. I managed to fix it but it's barely hanging on now. The repeater itself is installed in a rather benign environment (3 story medical office building) & I've been told there hasn't been any lightning in the area during the entire time it's been in operation. Also nothing else in the system suffered any damage during this time, including the Astron power supply, which never crowbarred. So my conclusion is that a bad batch of chip caps found their way into this unit. Given this conclusion & NHRC's failure to communicate with me on the 2nd failure I can't recommend their products, & have been looking for a non-NHRC replacement controller that would fit in the multi-freq area of an MVP. Looks like we finally have something available in the RC-99. Bob NO6B
