[Elecraft] ESD Risk vs Relative Humidity

[Wyn Hughes]

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
>
>