As in my prior post - ground both to the *same* grounding point. It does not have to be a good ground in the sense of RF or lightning ground, but it must be the *same* ground point. Remember that the "name of the game" is that everything should be at the same potential - and that need not necessarily be "zero volts = ground". It is the *difference* in potential between the points that you are working with or touching that should be zero, not that absolute potential with respect to "mother earth ground".
Does that not make sense considering that you are connecting the work surfaces to ground through a 1 megohm resistor. Gradual discharge of charged leads and surfaces is important to keep damage to an absolute minimum - so muffin tins connected to ground through a high value resistor are OK, and the anti-static foam placed on your anti-static mat before removing the ICs all will work fine. While I cannot dispute the advice to "touch a grounded metallic surface" offered in some of the Elecraft manuals (it is better than nothing), that does create an immediate discharge which can cause damage if the item being touched to the grounded surface is a lead of the IC device itself - the intent of that statement is to use the resistivity of your body to dissipate the charge - in other words, touch your hand to the grounded surface, but do not touch the lead of the IC directly to it. It is better to wear a wrist strap, and to work on an anti-static mat. Touch tools, free-floating conductors and the ICs to the mat before handling. The same goes for boards that have been removed from their native assemblies - those may have sensitive inputs which are not connected to their normal circuits, and can be a static-prone area. Once the components are assembled into their working (complete) circuit, the static damage concern should go away - except in extreme cases like lightning damage. 73, Don W3FPR On 12/18/2010 7:37 PM, david m wrote: > Yes. If you are using a commercially available wrist strap, the 1M > resistor is built in. An anti-static mat will also have a surface > resistivity of at least 1Mohm/sq. Ground both and you'll be safe, and > your equipment will be safe as well. > > On Sat, 2010-12-18 at 15:08 -0500, Don Wilhelm wrote: >> NOT a direct ground - through a high value (1 megohm) resistor, YES. >> That is basic SAFETY. >> >> Connecting your body directly to ground can cause bodily harm or even >> death if you accidentally come in contact with a source of voltage. >> Even low voltages can be dangerous if the source is capable of high >> current (such as a battery). >> >> For the same reasons, do not work on a fully conducting work surface - >> that may be fine for auto mechanic work, but should never be used to >> work on any electrical or electronic circuits. It is a matter of >> personal safety. > ______________________________________________________________ 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
