Question on "Going to Ground" aka throw the coax out the window !!

[W1UJR]

I wus just thinking that if a person were to use banana  plugs for the open wire type feeder, a spring loaded device of some sort could be put into use to disconnect the feeders if you let the storm get too close and were afraid to unhook it by hand. Press a button inside and Kazan, the feeders shoot off into the woods. 

Now you blew my patent!
I had it all connected to to my highly trained "trunk monkey" -->> http://www.youtube.com/watch?v=8avOiTUcD4Y

[KB2WIG]

FWIW,

An old EE told me that most of the guys had the feedlines do a 90 angle befoer entering the shack. The rationall was that lightning didn't like to turn corners....


klc

[WB2EMS]

Perhaps even more insidious is the buildup to the storm, or even snow static, again reference Tom's comments about HLR mountain.
I used to routinely see my feedline connection snap, crackle and pop with an approaching lightning storm, now I short them together.
My elmer, W2UJR SK, used to talk about "snow static", not something you often hear about today.
While that this may not harm most hollow state rigs, with solid state, I would not want to take a chance.

I had an FT757, my first solid state radio, zorched by snow static. I had a relatively low 75/160 meter dipole, coax fed. One windy, snowy, winter day here in central NY I started hearing arcs inside my MFJ antenna tuner while running some digital mode. I disconnected the coax right away, but it was too late. The radio had gone deaf. Yaesu repaired it and sent back a handful of dead pin diodes. (and forgot to reconnect the PA fan - next RTTY contact got *hot* before I figured that out)

I also used to get rain static when mobile. I was using a screwdriver antenna with an 8 foot whip. When I'd go through certain rainstorms, I'd get a rhythmic static pop, that would get worse and worse, sometimes turning into a squeal. Keying down would momentarily relieve it, but it would build up again pretty quickly. When I changed the feed to a coil off the bottom of the screwdriver (dc grounded) that problem went away.

As a JN, I recall seeing my long wire antenna arcing with distant and not so distant thunderstorms. It was about 100 feet of #28 (TV yoke winding) out of my second floor bedroom window to the swing set at the back of the yard. It was hooked to a BC348, with a neon NE-2 bulb across the antenna and ground. That would flash at various times. When a storm was coming, I'd disconnect it from the radio, but leave it lying on the desk. At times I'd hear it arcing to the radio chassis or other grounded lead. If I was home, I'd open the window and toss it out into the yard. Got a really good jolt one day when I was doing that and the lightning struck about 2 miles away (flash to boom time 10 seconds)

As a child, I used to really enjoy watching thunderstorms. Now as a ham, my wonder at their elemental beauty and fury is very much tempered by my awareness of how much wire and aluminum I have sticking up here and there.

[W2PFY]

trunk monkey

Good one Bruce, lots of good stories here. I guess we never get tired talking about our close call experiences, not to be confused with those "near misses" whatever the hell they are???

[W3SLK]

Terry said:

In the case where coax is used, a quarter pound of TNT could blow the line apart by a push of a button or perhaps the lighting bolt would set off the explosive and the resulting pressure wave would create a vacuum where the electrical path would be interrupted.

Hah! Don't think that is a too far-fetched idea. Not to change the course of the thread but I have a device at work that when it senses a rapid pressure rise, (ie explosion), in one of our dust collectors, it triggers a capacitor bank, which lights off a small amount of C-4, in turn ruptures a membrane on a cylinder of N2 @ 190 PSI which in the end forces out a Sodium Bicarbonate 'puck' that ultimately disperses and prevents the flame front from entering the building!

Anyone for a game of "Mousetrap"!! 

[W1UJR]

Who gets to test that Mike? :-)

[W2DU]

I remember as a kid in the late 1920s the antenna (oops, aerial) for the TRF radio was apx 75 feet long, with single leadin of insulated #14 house-wiring copper. Our heating system was central air, with the 3'x3' register in the center of the floor between the living and dining rooms. Was nice to lie down on on cold days.

Anyway, during snowstorms the static build-up on the antenna was terrific. We would remove the leadin from the receiver and hold the end of the wire close to the register (not grounded to anything) and the spark would jump for more than inch to the register. Not just once, but repeatedly after giving a few seconds for the charge to rebuild.

When holding the leadin by the insulation we didn't receive a shock, never felt anything, even when the spark was occurring. Something I'll never forget.

Walt

[WB4AIO]

I remember as a kid in the late 1920s the antenna (oops, aerial) for the TRF radio was apx 75 feet long, with single leadin of insulated #14 house-wiring copper. Our heating system was central air, with the 3'x3' register in the center of the floor between the living and dining rooms. Was nice to lie down on on cold days.

Anyway, during snowstorms the static build-up on the antenna was terrific. We would remove the leadin from the receiver and hold the end of the wire close to the register (not grounded to anything) and the spark would jump for more than inch to the register. Not just once, but repeatedly after giving a few seconds for the charge to rebuild.

When holding the leadin by the insulation we didn't receive a shock, never felt anything, even when the spark was occurring. Something I'll never forget.

Walt

Central air in the 20s -- pretty advanced! Plenty of houses today still don't have it.

Interesting that the lead-in didn't want to discharge through you, but only to the register. I speculate that somehow or other, perhaps through some high-resistance house path, you were already close to the same potential as the lead-in, but the register was not.

Soon it will be the 20s again!


With all good wishes,


Kevin, WB4AIO.

[W3SLK]

Bruce asked:

Who gets to test that Mike? :-)

I do Bruce. Every 3 mos. I have to verify the charge of the capacitor bank.