[Elecraft] K3 ESD

[Ian White GM3SEK]

David Pratt wrote:
>In a recent message, Kjeld Holm <kh at kh-translation.dk> writes
>>I am about to install my subreceiver  and would like to finish before the
>>weekend but I have no ESD work place. How can I best protect the parts? Or
>>do I have to wait until I can get the needed ESD equipment?

>Wear cotton clothing rather than nylon or highly static material; avoid
>walking around on static-prone carpets.  Wrap a length of bare copper
>wire around your wrist and solder a 2 megohm resistor to it.

Well, maybe do the soldering first...

The resistor can be 1 megohm or anything else in that region. It purpose 
is to limit any ESD current surge, and also to limit any accidental 
shock current in your body. For both of those reasons, the resistor 
should be at least 250V rated, and the wrist band must be insulated from 
any accidental contact (except to yourself).

>Connect
>that to a nearby ground connection.  Just ensure that the K3 is always
>at the same potential as yourself by touching its frame regularly.
>

NO - that is completely the wrong way around!  A "ground" connection to 
the Mother Planet will NOT ensure ESD protection.  If done without 
proper understanding, it is more likely to *increase* the risks to both 
the equipment and yourself.

The whole purpose of ESD protection is to minimize all voltage 
differences and current surges between your body and the electronic 
components, so connect your home-made wrist strap directly to the K3.

Since you do not have a proper ESD mat, place the K3 and KRX3 on a sheet 
of aluminium foil. Before opening the anti-static bag containing the 
KRX3, leave the bag on the foil for a short time to allow any static 
potentials to equalize.

You will then be working with a reasonable level of ESD protection. As 
it isn't necessary to connect any other mains-powered equipment or use a 
soldering iron while installing K3 option boards, grounding of the K3 
and the sheet of foil is purely optional.




-- 

73 from Ian GM3SEK
http://www.ifwtech.co.uk/g3sek