[Elecraft] Avoiding costly lightning damage to your radios gear

[Fred Jensen]

Yep, all true.  The somewhat insidious thing about precip static is that 
it can be totally innocuous, unlike T-storms, lightning strikes, and the 
like.  We hadn't even noted that it had begun snowing, fairly hard, 
outside the tent, when the first rx quit.  The "frying bacon" and the 
tiny little "grass" on the baseline of the panadapter should have been a 
clue to "look outside" to a bunch of OF's with that much accumulated 
experience ... sadly it wasn't.  OTOH, QRN from multiple distant 
T-storms is just that ... annoying noise in the receiver with no danger. 
Likewise with power line hash.  Of all the forms of QRN, and excluding a 
lightning strike [which is hard to ignore], precip static can be the 
most dangerous to equipment and go unrecognized by new folk [and a 
handful of OT's].

In this age with a dearth of Elmers standing next to you, that function 
seems to have migrated to email lists like this one, various fora, and 
various wiki's.  I don't think they can replace W6RMK, with my latest 
electronic creation [usually a TX] on his bench, explaining how the grid 
of the PA rectifies some of the RF waveform and charges a capacitor that 
slowly leaks off through an appropriately named "grid leak" resistor. [:-)

73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 10/31/2018 4:14 PM, Don Wilhelm wrote:
> Skip,
>
> Yes, there are various causes of static on the feedline, but static is 
> static.  It is a voltage charge on the feedline and it can damage 
> equipment.
> The source may be wind blowing on your antenna, rain or snow that 
> carries charged particles, or nearby lightning.  No matter what the 
> cause, it can produce a significant voltage across your feedline.  It 
> does not take a direct lightning hit to produce damaging voltages on 
> your antenna feedline.  A direct hit can cause damage to house and 
> home and any equipment in that home, but there are other times when 
> the accumulated static voltage on any feedline can cause damage to 
> your ham equipment.
>
> I recall an event many years ago when I got that lesson.  I had 
> several antennas in the basement shack unterminated and just waiting 
> to be connected.  The wind was blowing and I thought nothing of it 
> until I picked up an open feedline and placed it near my Heathkit 
> HW101 intending to connect it - sparks flew as the coax got close to 
> the chassis!  That was a warning to me - disconnect and ground all my 
> feedlines when not in use.  If not grounded, at least a bleed resistor 
> across the feedlines to discharge any built up static.
>
> 73,
> Don W3FPR
>