[Elecraft] Upgrading a K3?

[Alan]

Yup, that was me.  The Radio Shack portable mat in particular is one 
that my testing showed to have too high a resistance to do any good.

The one Walter mentions (below) is probably OK.  The Amazon page 
specifies "Surface resistivity: 10E9 - 10E11 Ohm/m2" and it mentions 
that the back side is black and 1.8 mm thick.  Good mats have a 
highly-conductive back side to properly distribute the charge.

I agree that using an anti-static mat and wrist strap is good insurance. 
  The reason for grounding it is to make sure it is at the same 
potential as any grounded device (such as a soldering iron) that you may 
be using.

Alan N1AL


On 12/22/2017 07:59 PM, Ron D'Eau Claire wrote:
> Be aware that some "antistatic" mats are just pieces of soft vinyl without any real antistatic properties.
> 
> One of the Elecraft engineers studied several mats and came up with the following information included in the newer Elecraft manuals:
> 
> "Typically, a mat will have a resistance of up to 1 Gigaohm (109 ohms). Testing a mat requires specialized equipment, so we recommend that you choose an anti-static mat that comes with published resistance specifications and clean it as recommended by the manufacturer.
> 
> "Testing has shown that many inexpensive mats that do not specify their resistance have resistance values much too high to provide adequate protection, even after they were cleaned
> and treated with special anti-static mat solutions.
> 
> "Suitable anti-static table mats are available from many sources including:
> • U-line (Model 12743 specified at 107 ohms)
> • Desco (Model 66164, specified at 106 to 108 ohms)
> • 3MTM Portable Service Kit (Model 8505 or 8507, specified at 106 to 109 ohms)"
> 
> 73, Ron AC7AC
> 
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of John Stengrevics
> Sent: Friday, December 22, 2017 11:26 AM
> To: Walter Underwood
> Cc: elecraft
> Subject: Re: [Elecraft] Upgrading a K3?
> 
> I agree.  I was a total neophyte when I assembled my K3S.  I used a cheap mat and wrist band.  Never had a static failure.  As Walter said, cheap insurance.
> 
> John
> WA1EAZ
> 
>> On Dec 22, 2017, at 2:22 PM, Walter Underwood <wunder at wunderwood.org> wrote:
>>
>> When working on tube gear, keep one hand in your pocket. When working on solid-state gear, keep one hand on the chassis.
>>
>> But a static mat is cheap insurance for when you need to scratch your nose.
>>
>> Amazon has one for $11. I think I paid more for mine at Fry’s, but whatever.
>>
>> https://smile.amazon.com/Velleman-AS4-Anti-Static-Ground-Cable/dp/B001IRVCJC/
>>
>> wunder
>> K6WRU
>> Walter Underwood
>> CM87wj
>> http://observer.wunderwood.org/ (my blog)
>>
>>> On Dec 22, 2017, at 11:08 AM, rkruse at johngalt.biz wrote:
>>>
>>>
>>>
>>> On 12/22/2017 12:16 PM, G4GNX wrote:
>>>> Firstly, you absolutely MUST use an anti-static mat, suitably connected to ground and an anti-static wrist strap.  ...