On Mon, 26 Jan 2004 14:14:21 -0500, "Jack Painter"
wrote:

But I guess the the
currents in the coax weren't "near enough equal" in this one case.

This is the definition of Common Mode.

Kind of
defines lightning as it's own anomoly when it wants to be, huh.

It means you lacked the Common Mode protection. Your earlier posting
of:

The coax in question was disconnected about 150' from the house, but
lightning apparently jumped from the tower feed across a foot of air space
and back into the PVC pipe channel housing several coax, which led to the
house. The Drake was the luckiest of the second-story ungrounded shack gear.

screams this big time. There was nothing anomalous about that
lightning strike, it did what it was enabled to do.

73's
Richard Clark, KB7QHC

"Richard Clark" wrote

It means you lacked the Common Mode protection. Your earlier posting
of:

The coax in question was disconnected about 150' from the house, but
lightning apparently jumped from the tower feed across a foot of air
space
and back into the PVC pipe channel housing several coax, which led to
the
house. The Drake was the luckiest of the second-story ungrounded shack
gear.

screams this big time. There was nothing anomalous about that
lightning strike, it did what it was enabled to do.

Richard, do you mean that if the coax had been left connected to the dipole
it would have afforded common-mode protection? I think I understand what
you're saying but would appreciate you tying that principle together.
Thanks.

Jack

On Mon, 26 Jan 2004 16:02:38 -0500, "Jack Painter"
wrote:


Richard, do you mean that if the coax had been left connected to the dipole
it would have afforded common-mode protection? I think I understand what
you're saying but would appreciate you tying that principle together.
Thanks.

Jack

Hi Jack,

Ask yourself "Where is ground in this picture?"

THAT is the Common of the Common Mode. I see it discussed nowhere in
your description. There is the inference of it being back in the
house (code requires it) where lightning eventually found it, the hard
way.

As you describe it:
The coax in question was disconnected about 150' from the house,
disconnected where, how? Up the tower? At the bottom of the tower?
Is the tower grounded? Does the tower ground meet code in being tied
to the house ground? Is the coax grounded? Where? Does it supply
ground? Where?

The Drake was the luckiest of the second-story ungrounded shack gear.
No ground? There are two problems with this statement.
1.) It is unlikely due to code;
2.) It means you accept Common Mode problems.

It being unlikely does not mean you are protected (experience proves
this), it means you went with the flow - of several KV.

73's
Richard Clark, KB7QHC

Richard, my earlier posts described the grounding my friend, here is quick
summary:

1.Well grounded 100' tower, hundreds of feet of many radials, rods, etc.
Survived many strikes.
2. Feedline from tower's dipole was disconnected about 20' from tower where
it enters a buried pvc conduit that travels 150' to house, then up to second
story shack. Where nothing is grounded, except by virtue of house AC
wiring - a bad I know (not mine either).
3. Ground current from the tower strike most likely entered the coax
feedlines at the disconnect point as they entered the pvc conduit then
traveled on into house.
4. House current also took huge jolts, zorching all kinds of connected
equipment, phones, tv's etc.
5. Outbuilding with radio equipment connected took huge hit, ball lightning
inside room fried test cords connected to nothing, hanging on test bench,
where the leads touched tile floor, huge blow-out of tile. AC power blew
wall warts across room, computers next to each other had .22 rifle bullet
sized hole between them. Equipment in this bldg was grounded, and some that
was was damaged, others not touched. In short, a massive, multiple
strike-path hit that may not be protectable from - but I realize there was a
lot missing from a good ground picture here also.

Jack

"Richard Clark" wrote
Ask yourself "Where is ground in this picture?"

THAT is the Common of the Common Mode. I see it discussed nowhere in
your description. There is the inference of it being back in the
house (code requires it) where lightning eventually found it, the hard
way.

As you describe it:
The coax in question was disconnected about 150' from the house,
disconnected where, how? Up the tower? At the bottom of the tower?
Is the tower grounded? Does the tower ground meet code in being tied
to the house ground? Is the coax grounded? Where? Does it supply
ground? Where?

The Drake was the luckiest of the second-story ungrounded shack gear.
No ground? There are two problems with this statement.
1.) It is unlikely due to code;
2.) It means you accept Common Mode problems.

It being unlikely does not mean you are protected (experience proves
this), it means you went with the flow - of several KV.

73's
Richard Clark, KB7QHC

On Mon, 26 Jan 2004 21:07:24 -0500, "Jack Painter"
wrote:

Richard, my earlier posts described the grounding my friend, here is quick
summary:

1.Well grounded 100' tower, hundreds of feet of many radials, rods, etc.
Survived many strikes.
2. Feedline from tower's dipole was disconnected about 20' from tower where
it enters a buried pvc conduit that travels 150' to house, then up to second
story shack. Where nothing is grounded, except by virtue of house AC
wiring - a bad I know (not mine either).
3. Ground current from the tower strike most likely entered the coax
feedlines at the disconnect point as they entered the pvc conduit then
traveled on into house.
4. House current also took huge jolts, zorching all kinds of connected
equipment, phones, tv's etc.
5. Outbuilding with radio equipment connected took huge hit, ball lightning
inside room fried test cords connected to nothing, hanging on test bench,
where the leads touched tile floor, huge blow-out of tile. AC power blew
wall warts across room, computers next to each other had .22 rifle bullet
sized hole between them. Equipment in this bldg was grounded, and some that
was was damaged, others not touched. In short, a massive, multiple
strike-path hit that may not be protectable from - but I realize there was a
lot missing from a good ground picture here also.

Jack

Hi Jack,

You know, it sounds like the lightning hit your house/out-building and
went toward the tower.

73's
Richard Clark, KB7QHC

Richard Clark wrote in message . ..
On Mon, 26 Jan 2004 21:07:24 -0500, "Jack Painter"
wrote:

Richard, my earlier posts described the grounding my friend, here is quick
summary:

1.Well grounded 100' tower, hundreds of feet of many radials, rods, etc.
Survived many strikes.
2. Feedline from tower's dipole was disconnected about 20' from tower where
it enters a buried pvc conduit that travels 150' to house, then up to second
story shack. Where nothing is grounded, except by virtue of house AC
wiring - a bad I know (not mine either).
3. Ground current from the tower strike most likely entered the coax
feedlines at the disconnect point as they entered the pvc conduit then
traveled on into house.
4. House current also took huge jolts, zorching all kinds of connected
equipment, phones, tv's etc.
5. Outbuilding with radio equipment connected took huge hit, ball lightning
inside room fried test cords connected to nothing, hanging on test bench,
where the leads touched tile floor, huge blow-out of tile. AC power blew
wall warts across room, computers next to each other had .22 rifle bullet
sized hole between them. Equipment in this bldg was grounded, and some that
was was damaged, others not touched. In short, a massive, multiple
strike-path hit that may not be protectable from - but I realize there was a
lot missing from a good ground picture here also.

Jack

Hi Jack,

You know, it sounds like the lightning hit your house/out-building and
went toward the tower.

73's
Richard Clark, KB7QHC

Sounds like it. I'm fairly sure it didn't hit the tower. Or if it did,
it also hit the houses at the same time. You don't get dime size holes
in the house, unless the strike is traveling in the house. I don't
think it's too likely ground currents traveled up the unconnected coax
to the house. It would have gone on to ground at the tower, being it's
well grounded. I think the upstairs part of the house was struck, and
the coax from the drake, along with power wiring was the return to
ground. Note all the damage in the house. Jack, you are one lucky $#^
*#^*@.... It could have burned the house down. The coax to ground
level from the upstairs drake may have routed a good bit of the strike
out to ground. Not enough to save damage though..MK

Thanks to all responding. A 20m antenna on top of the tower was demolished,
pieces landing 100' away. That one single feedline was connected and
operating a wx-alert system in the shop. The house suffered zero structural
damage, the roofline and 2 antennas on it was definitely not the source of
any of the strikes. The outbuildings also suffered no structural damage or
even marks. The coax(s) most definitely carried the lightning, now whether
they got it from the ground current, tower, tower ground radials, that's
anybody's guess. Coming into the shop, that was likely from the 20 meter
feedline, but the explosion inside the shop right next to my friend was just
"energy", the same kind that blew up floor tile from a patch cord hanging on
a hook by itself. The computers destroyed were from energy in the AC wiring
and cable modem network.

From all I have read here, this hit was (luckily) one of rare intensity and
diversity. Two strikes to the tower later in the summer of last year had
only minor impact on anything.

Jack


"Mark Keith" wrote
On Mon, 26 Jan 2004 21:07:24 -0500, "Jack Painter"
wrote:

Richard, my earlier posts described the grounding my friend, here is
quick
summary:

1.Well grounded 100' tower, hundreds of feet of many radials, rods,
etc.
Survived many strikes.
2. Feedline from tower's dipole was disconnected about 20' from tower
where
it enters a buried pvc conduit that travels 150' to house, then up to
second
story shack. Where nothing is grounded, except by virtue of house AC
wiring - a bad I know (not mine either).
3. Ground current from the tower strike most likely entered the coax
feedlines at the disconnect point as they entered the pvc conduit then
traveled on into house.
4. House current also took huge jolts, zorching all kinds of connected
equipment, phones, tv's etc.
5. Outbuilding with radio equipment connected took huge hit, ball
lightning
inside room fried test cords connected to nothing, hanging on test
bench,
where the leads touched tile floor, huge blow-out of tile. AC power
blew
wall warts across room, computers next to each other had .22 rifle
bullet
sized hole between them. Equipment in this bldg was grounded, and some
that
was was damaged, others not touched. In short, a massive, multiple
strike-path hit that may not be protectable from - but I realize there
was a
lot missing from a good ground picture here also.

Jack

Hi Jack,

You know, it sounds like the lightning hit your house/out-building and
went toward the tower.

73's
Richard Clark, KB7QHC

Sounds like it. I'm fairly sure it didn't hit the tower. Or if it did,
it also hit the houses at the same time. You don't get dime size holes
in the house, unless the strike is traveling in the house. I don't
think it's too likely ground currents traveled up the unconnected coax
to the house. It would have gone on to ground at the tower, being it's
well grounded. I think the upstairs part of the house was struck, and
the coax from the drake, along with power wiring was the return to
ground. Note all the damage in the house. Jack, you are one lucky $#^
*#^*@.... It could have burned the house down. The coax to ground
level from the upstairs drake may have routed a good bit of the strike
out to ground. Not enough to save damage though..MK