[Elecraft] ESD Risk vs Relative Humidity

[Joe Wilkowski]

My 2c worth.  I have posted on this reflector before my experiences with ESD 
and my K2 as I was building it.  First, understand that  I live in the 
mountains of Colorado at about 8200' ASL.  It is extremely dry here all year 
round and especially in the winter months when the RH rarely gets above 60 % 
To make matters worse, we are remote enough so that our home is 100% 
electric which is expensive so we supplement the heat with two wood burning 
stoves up and down.  There isn't much more we can do to put humidity in our 
air than to keep fancy water pots filled on top of each stove.

I have read many comments here before on the ability of the K2 to withstand 
ESD discharges but I can attest to having to do a complete reset of the K2 
and reload all parameters on two occasions this season.  Both of these 
instances occurred during the later stages of construction and alignment. 
These ESD related issues occurred while I was wearing a ESD wrist strap tied 
to the ground/neutral buss of the house supply.  ESD is real and the K2 is 
definitely NOT immune.  Since completion, and while the radio was fully 
buttoned up with all panels, the K2 has suffered ESD shutdowns of audio and 
other functions but was quickly remedied by cycling the power.  It seems at 
times that  I cannot move around in my chair without zapping the little rig. 
So my recommendation is to utilize ESD protection at all times when 
constructing or working on the interior of the rig.  Again, your mileage may 
vary but these are my experiences.

/joe k8fc
----- Original Message ----- 
From: "Mike Short" <mike.short at mchsi.com>
To: <Elecraft at mailman.qth.net>
Sent: Wednesday, December 20, 2006 5:24 AM
Subject: RE: [Elecraft] ESD Risk vs Relative Humidity


> ESD damage does not always show up immediately. ESD can "stunt" the life 
> of
> components.
> Instead of lasting 5 or 10 years, you may only get a few years out of 
> them.
> I have had a lot of training in the military on ESD, and they spend big
> bucks on equipment
> And training. The avionics building I worked in in Germany had ESD tile on
> the floors, as well as grounded benches, mats
> And straps, etc.
>
> Mike
> AI4NS
>
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Wyn Hughes
> Sent: Tuesday, December 19, 2006 7:20 AM
> To: Mike Harris; elecraft at mailman.qth.net
> Subject: Re: [Elecraft] ESD Risk vs Relative Humidity
>
> Mike and Don,
>
> Thanks for your input. I suspect that ESD damage occurs more often than 
> one
> realises.  Don's report confirms. I read reports that quite a few of the
> NATO IC-781s went down in the last gulf conflict for no apparent reason,
> other than microprocessor failure suspected due to the extreme low 
> humidity.
> I have experienced some strange and otherwise wholly inexplicable PC
> failures due to early working without a wrist strap in the past. For 
> safety
> sake I will stick with the new mat amd its combined wrist strap. Then at
> least I will eliminate one possibility from my shopping list of problem
> causes.
>
> Best 73
> Wyn, VR2AX
>
>
>
>
> ----- Original Message -----
> From: "Mike Harris" <mike.harris at horizon.co.fk>
> To: "Wyn Hughes" <vr2ax at attglobal.net>; <elecraft at mailman.qth.net>
> Sent: Tuesday, December 19, 2006 5:42 AM
> Subject: Re: [Elecraft] ESD Risk vs Relative Humidity
>
>
>> G'day,
>>
>> <snip>
>> Today in Hong Kong we have relative humidity (RH) of 55% (temp a
>> 'freezing' 16 C), compared to our norm of 90 - 100% RH and temp 30 C+
>> <snip>
>>
>> I assume the 16C was outside not inside.
>>
>> <snip
>> These past two days my daughter and xyl have mentioned several 'static
>> shocks' when they play with our cats, all 6 of them.
>>
>> I remember my school kid days of cats tail static generators, but there's
>> a serious question behind this. Under what conditions of RH do most
>> builders of Elecraft rigs operate?
>> <snip>
>>
>> RH in the house is of the order 40-60% temp 20-22C most of the time.  No
>> cats, no ESD countermeasures besides touching an earthed object before
>> picking up sensitive devices.  Not killed one yet.
>>
>> Regards,
>>
>> Mike VP8NO
>>
>>
>
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