It's great "Ham" tradition to look for the cheapest and most effective way to get the job done, but there comes a time when doing it "by the numbers" is a great investment to reduce the chances of a costly mistake.
It's like avoiding the one word us non-physicians ever want to hear if we're in surgery. (That word, of course, is the surgeon saying "Oops!"). If anything, I believe modern active devices are more sensitive than the older stuff. Of course, it's hard to "fry" a bipolar transistor compared to insulated-gate (e.g. MOSFETs), and the older stuff used a LOT of bipolar devices where MOS devices are used today. But even MOS stuff has grown more sensitive as the designs have evolved to provide for faster switching (higher data speeds) and lower power consumption. Those demands mean thinner and more delicate insulation in the gates and it's that insulation that's quickly and easily compromised by even small static charges. For a while early MOSFETs often included back-to-back diodes on the substrate to "protect" the gates from low level ESD since the diodes would turn on if their forward conduction voltage was exceeded. However, such diodes add unwanted capacitance to the circuit which limits the switching speed and are not commonly used today AFAIK. Bottom line, the newer stuff is easier to fry if one gets careless about ESD. Avoid the "Oops!" ;-) Ron AC7AC -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Gary Smith Sent: Saturday, December 13, 2008 9:49 AM To: [email protected] Subject: Re: [Elecraft] easy source of static dissipating work mat? So many good idears regarding the mat. I've decided to go with & bought last night, the mat from Radio Shack. I doubt there'd be much likelihood of problem as I've never fried anything in computer assembly since I first assembled a Heathkit H8 (which I used as a bulletin board back in 78) but this is the most expensive kit I've ever assembled & I do my best to avoid mistakes. Thanks for the great suggestions, I'm sure this will be fine for the task. 73, Gary KA1J _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
