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-boun...@mailman.qth.net
[mailto:elecraft-boun...@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 <wun...@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, rkr...@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. ...
______________________________________________________________
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
Message delivered to arch...@mail-archive.com
