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
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