[Elecraft] easy source of static dissipating work mat?

[Ron D'Eau Claire]

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: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Gary Smith
Sent: Saturday, December 13, 2008 9:49 AM
To: Elecraft at mailman.qth.net
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