As I observed to Dick, n0ce: It's been a long, long road from the early low-impedance bipolar transistors to the modern ultra low power FETs.
There was a time we worried about getting hurt: knocked on our keister by accidentally touching high voltage or burning our fingers on a hot vacuum tube. Now the tables are turned and we have to worry more about the equipment. 73, Ron AC7AC -----Original Message----- From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Don Wilhelm Sent: Monday, September 19, 2016 1:59 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] Anti-static Pads Hi all, While I can state that Ron's comment about the K2 is typically true, the static tolerance of thru-hole ICs and transistors is lower than it was back in 1998 or even 2006 (OK, I picked those years as a guess). Many DIP mounted devices are really SMD devices with DIP leads and can be as static sensitive as the devices in the K3 and KX3. Despite the "touch grounded metal" instruction in the K2 manual, I do see some repairs come in with failed firmware ICs, and rarely, but not zero, some 'normal' ICs on a new build. My best guess is that those parts were damaged due to a static charge. Whether the builder did not follow the "touch a metal ground" or not I cannot tell, all I know is that it failed. When possible, use an anti-static mat and wrist strap when handling ICs and transistors, especially during periods of low humidity. Do not work on carpet without them and do not wear nylon clothing - and don't shuffle your feet on the floor while working. The minimum should be a wrist strap connected to the green-wire ground in your house. You can use a banana plug in the round pin of an electrical receptacle, but before you trust it, get one of the receptacle testers and make sure that green wire ground is intact - some are not. Whether your anti-static precautions are 'overkill' for the task to be accomplished will never be known. Take whatever precautions make you feel comfortable with the risk factor involved. Doing nothing or ignoring the static damage probability is not acceptable unless you are willing to accept the risk. I suggest that you do not connect the wrist strap to a separate ground rod that you have for your hamshack unless that ground rod is also bonded to the utility entrance ground rod. It is off this topic, but if your ground rods are not connected to the utility entrance ground, it is a safety hazard should something in the house *or* your shack develop a fault. In addition, it is a violation of the NEC (those codes are written for your safety). 73, Don W3FPR ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
