[Elecraft] Upgrading a K3?

Fri Dec 22 22:59:39 EST 2017

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/B001
> IRVCJC/
> 
> 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. Whilst you might "get away with it" without those items, you may cause unseen damage and you won't know until it breaks down. I know the manuals state that you can "touch a metal object", but that's very hit and miss. 
>> 
>> I'm going to respectfully disagree.  The problem is not the static or the ground, the problem is when you have a differential voltage between items.
>> 
>> If you always maintain a forearm on the frame of your device and handle things carefully while maintaining contact with the frame, you will all be at the same electrical potential.  Be sure to be in contact with the frame when opening anti-static bags, too. Hold boards by the edges, don't finger the gold contacts, and don't touch components if you don't have to.
>> 
>> This technique has worked for me for years.  I don't do sensitive work often, but I never seem to have all the 'anti-static' stuff when I need it.
>> 
>> The only danger is if you get carried away and lift that arm.
>> 
>> 73
>> 
>> Ray
>> KK4WPB
>> 
>> Molon labe
>> 
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