[HCRA] Fw: KB6NU's December 2013 Column: Protect your gear fromESD

Mon Jan 6 18:35:24 EST 2014

Here's another problem that has happened to me.

This past weekend I read an article about electrostatic induction.
Unfortunate the article was incorrect. Here's what can happen: 

Lightning can induce a charge unto a line, such as a power or telephone
line. No direct hit is required, just the act of the bolt passing near the
line will do the trick. This induced charge then finds the best way for it
to complete a circuit to ground.

If that happens to be via a telephone line, well, there goes those cheap
Chinese phones, or in my case a FAX machine. 

Later I found out that the FAX machine has a fuse on each wire of the pair.
The fuse looked like a surface mount capacitor, so I didn't suspect it
until I thought "why would there be a capacitor in series with the line?"
After that the repair was simple.

I wouldn't doubt that a similar problem could happen between a phone line,
computer and grounded radio. Unfortunately there are some electronics in
that path, which get zapped in the process.

Jim, W1EQO

Original email:
-----------------
From: James Saccento james at saccento.com
Date: Mon, 6 Jan 2014 13:19:43 -0500
To: WB1DBY at comcast.net, hcra at mailman.qth.net
Subject: Re: [HCRA] Fw: KB6NU's December 2013 Column: Protect your gear
fromESD

______________________________________________
-------Hampden County Radio Association-------
-----------e-mail list (reflector)-------------
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I wanted to add that after talking to Kenwood support this fall, they
report that a large percentage of radios are now being zapped through
surges from attached computers.  People disconnect their feed lines but
leave the USB or serial connector attached and when the PC gets hit it
jumps to the radio.  I personally had my radio's USB card blown out from
lighting hitting my phone line - on to the DSL modem - jumping to the
attached Ethernet switch - through 100 feet of CAT5e Cable to the PC, and
finally into the radio via USB.

James
WD1S

On Sun, Jan 5, 2014 at 8:58 AM, Larry Krainson <WB1DBY at comcast.net> wrote:

> ______________________________________________
> -------Hampden County Radio Association-------
> -----------e-mail list (reflector)-------------
> ______________________________________________
>
>
>
>
> Hi, all--
>
> Here's my December 2013 column.
>
> 73!
>
> Dan KB6NU
>
>
> <--  start column  -->
>
> Protect your gear from ESD
>
> Electrostatic discharge, or ESD for short, has been a concern for anyone
> involved in electronics ever since we made the transition from vacuum
tubes
> to transistors. I was schooled about ESD when I worked as a test engineer
> for a company called Doric Scientific shortly after I got out of
> engineering school, and I wrote about it when I was an editor for
> Test&Measurment World magazine back in the 1990s. If anything, it's even
> more of a concern today as electronic components get ever smaller.
>
> In 1991, Bryan P. Bergeron, NU1N, published a two-part series on ESD (part
> 1: http://www.arrl.org/files/file/Technology/tis/info/pdf/9104019.pdf,
> part 2:
http://www.arrl.org/files/file/Technology/tis/info/pdf/9105028.pdf)
> in QST. His suggestions about how to prevent ESD damage are as good now as
> they were 20 years ago:
>
>  - Consider using a room humidifier to increase the relative humidity in
> your shack, or wherever you work on electronic equipment to 65% RH or
> higher.
>  - Use grounded wrist straps when handling ESD-sensitive devices.
>  - Use grounded, anti-ESD work mats when working on electronic equipment.
>  - Use a grounded soldering iron and anti-static tools.
>  - Use anti-static bags and containers for storing and transporting
> electronic equipment.
>  - Connect the chassis of all your gear to a good earth ground.
>  - Consider purchasing a desktop ionizer to neutralize static buildup on
> your workbench.
>
> I might also add consider grounding the chairs that you use in your shack
> or discharging yourself after getting up from the chair in your shack. I
> know that the worst electrostatic discharges that I experience  are after
I
> get up from my chair. You can even buy ESD-safe chairs (
> http://www.all-spec.com/products/Benches_and_Chairs%
> 7CChairs_and_Accessories%7CCHR-00/), but they are kind of expensive.
>
> Personally, I use an anti-static mat that I originally purchased for use
> with a computer keyboard and a wrist strap that was given to me by an ESD
> consultant when I worked for the magazine. I use these religiously when
> building kits or working on any solid-state gear.
>
> It's not hard to find anti-static products. RadioShack sells a wrist strap
> for only $1.23 (http://www.radioshack.com/product/index.jsp?productId=
> 2103245)! You can find a whole range of anti-static products on Amazon,
> too. Wherever you get them, they're a good investment.
>
> ===================================================
>
> When he's not worrying about ESD, Dan, KB6NU enjoys teaching amateur radio
> classes and working CW on the HF bands. For more information about his
> operating activities and his "No-Nonsense" series of amateur radio license
> study guides, go to KB6NU.Com or e-mail cwgeek at kb6nu.com.
>
>
> <--  end column  -->
>
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