[Elecraft] K3 #4407 - dead

[Joe Subich, W4TV]

 > I strongly agree. Proper bonding is probably more important than
 > protection devices (although I wouldn't do without either). And
 > IMPROPER bonding, or missing bonding, is a common CAUSE of lightning
 > damage.

Not to be piling on ... but improper bonding will GUARANTEE lightning
damage.  Any system that lacks proper bonding will assure that the
transceiver and computer are connected to two grounds that WILL have
a significant voltage difference in the event of a nearby lightning
strike or significant power surge.

As soon as the ground potentials diverge by more than 5 Volts you have
the possibility that logic devices will be damaged due to "reverse
voltage" when the chassis ("ground potential") in one device goes
above the power supply voltage in the other device.  This can happen
if the RF ground (coax shield) goes positive with respect to the
safety ground (grounding pin on the power cable) or if the safety
ground goes high with respect to the RF ground.

 > This is especially true when shunt mode protection is in use (MOVs,
 > for example).

MOVs on power distribution circuits can very easily cause the "safety
ground" to reach several hundred volts in improperly wired (open ground
or reversed ground and neutral) installations.  Unless you are 100%
sure that your home/shack is properly wired and bonded, the *ONLY*
place you should have shunt mode protection is at the service entrance
(meter) or primary circuit breaker panel (what is known as "whole
house" protection).

73,

    ... Joe, W4TV


On 8/12/2010 3:09 PM, Jim Brown wrote:
> On Thu, 12 Aug 2010 10:32:59 -0400, Tom W8JI wrote:
>
>> I'm going to disagree with the popular but misplaced notion that when
>> lightning hits nothing can be done to prevent damage other than a complete
>> disconnect.
>
>> The real problem is almost always that people pepper the station with
>> protection devices but use poor wiring layouts or poor entrance schemes. 99%
>> of the protection is in  the layout and bonding, not in the protection
>> devices we throw into the system.
>
> I strongly agree. Proper bonding is probably more important than protection
> devices (although I wouldn't do without either). And IMPROPER bonding, or
> missing bonding, is a common CAUSE of lightning damage. This is especially
> true when shunt mode protection is in use (MOVs, for example).
>
> 73, Jim Brown K9YC
>
>
>
>
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