[Elecraft] antistatic mat for K3 assembly

KBG Luxford kbgluxford at fastmail.fm
Mon May 12 04:05:43 EDT 2008


Hi Franki,

I would suggest that you find a way of connecting the crocodile clip to 
mains Earth in some way.  Maybe you have a piece of equipment with a 
metal case which is connected to your electrical supply by a three prong 
plug (hot, neutral and earth).  You do need to make sure that the case 
is connected to the earth prong on your plug which you can do by an 
ohmmeter connected to the case and the earth prong after the plug has 
been withdrawn from the electrical outlet.  Once you have established 
that the connection from the metal case to the earth prong is intact, 
then put the plug back into the supply outlet, (no need to switch on the 
equipment) and clip the crocodile clip to an unpainted part of the case.

I can not advise you on how essential would be an anti-static mat, 
however, they are not expensive and certainly far less than the cost of 
replacing sensitive components.

In my own case, I have mounted a number of power boards on a metal case, 
and power to the whole lot is controlled by a 15 amp rocker switch 
containing a neon light.  The power boards are used to supply power to 
test equipment, soldering irons and so forth, not more than two or three 
items are actually on at the same time.  I have also included a 15 Amp 
moving iron meter to monitor the total current drawn from the power 
supply system.

This means only one switch is needed to control all the power to my 
workshop.  And other family members can see whether the old man has left 
the power on or not - especially when we are all vacating the house for 
some time.

Now down at the bottom of the metal panel, I have three, green coloured 
4 mm banana sockets for plugging in anti-static mats and wrist straps. 
The banana sockets, of course, are all connected to mains earth.

The anti-static wrist-strap should have something like a 1 megohm 
resistor between the conductive strap and its connector at the end of 
its spiral cord.  The resistor does not impede the draining of charge, 
and it is there to help protect you in case you touch something at a 
dangerous potential.

I hope that this is of some help to you.

73
Kevin
VK3DAP / ZL2DAP





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