Antenna Down

Whitehall · Feb 28, 2006

Northern California is getting hit with a blustery winter storm and last night my antenna blew down.

It was a chimney mount using two stainless steel straps around the brickwork. I had reinforced the chimney with heavy angle irons on each corner. The strap clamps had short standoffs to the mast clamps. Looks like the failure occurred here but wouldn't get to the roof until the storm is over and the wood shingles dry.

The mast was 8 feet or so then had a rotator and another two foot mast to the big Winegard.

I had mounted the mast on the corner of the chimney away from the power entrance to the house for safety so it fell in the safe direction.

Lefty · Feb 28, 2006

Whitehall said:
Northern California is getting hit with a blustery winter storm and last night my antenna blew down.

It was a chimney mount using two stainless steel straps around the brickwork. I had reinforced the chimney with heavy angle irons on each corner. The strap clamps had short standoffs to the mast clamps. Looks like the failure occurred here but wouldn't get to the roof until the storm is over and the wood shingles dry.

The mast was 8 feet or so then had a rotator and another two foot mast to the big Winegard.

I had mounted the mast on the corner of the chimney away from the power entrance to the house for safety so it fell in the safe direction.

Well the old saying goes "if your antenna didn't fall down last winter then it ain't big enough"

Sorry for the loss, hopefully you will determine the root failure and be go to go once again. And yea it has been quite the blowin' storm the last couple of days, tornado alerts in Solano county earlier this morning.

Lefty

Sandy G · Feb 28, 2006

Aww, man...Hate to hear that. How bad is yr Winegard boogered up ? Is the rotator toast ? Hope you can get 'er up again real soon...But, PLEASE, be careful...-Sandy G.

dew042 · Feb 28, 2006

Your antenna won't matter much when California slides into the ocean. It'll happen.

dew.

outlawmws · Feb 28, 2006

dew042 said:
Your antenna won't matter much when California slides into the ocean. It'll happen.

dew.

Actually everyone has it backwards, All the California eathquakes are California trying to shake off the rest of the country! When it happens, we will be the only thing left! Sorta like Atlantis sinking!

:lmao:

ron-c · Feb 28, 2006

And your car will look like a golf ball in the spring hail storms...BWHaaaaaa!

California Ron-C

markthefixer · Feb 28, 2006

Seriously, I vote for a flexure failure, brought on by the repeated swaying in the wind. When I put up the antenna on my house, I didn't use the chimney as a mount, I put lead anchors into the brick wall with 8 inch mast standoffs widely spaced. Everything was radio shack circa 14 years ago.

I would take a picture, but it's too dark.

Later on I was glad when the chimney started showing signs of problems. Tuckpointing needed, possibly new cap and bird guards. I'm waiting until either I get a new high-efficiency furnace, necessatating a re-line or liner etc...
Or it succumbs to gravity.

We've had some pretty good microbursts come through over the years.

Good luck on the re-installation, and it would be great to see pictures of what let loose.....

Whitehall · Feb 28, 2006

When I installed it, I did notice that the mast and antenna was rather springy.

Had a break in the weather today so got some photos. Looks like the stainless steel strapping failed in tension.

warnerwhf · Mar 1, 2006

Now you tell me. My antenna blew off a few weeks ago. It had been on the side of the house. I have a brand new chimney mount I'm planning on using thinking that unless the chimney came down I'd be ok. Maybe I'll mod it to make it stronger. Fortunately my antenna hadn't been damaged at all. Even sitting leaning against the fence I pick up everything fine.

Whitehall · Mar 1, 2006

One guy on the FM Tuners group suggested fatigue failure of the strap due to poor installation. That's plausible since I did my usual hack job on it - my first time with strapping so it was bent and crimped.

Unless I come up with something better, I'll just get another trap mount and use it, maybe keep the lower strap so that I have three straps on it.

markthefixer · Mar 1, 2006

Well from the pictures, I think for a chimney installation, it was a good job.
I liked the full length corner protection to spread the stress.
It looks like the chimney does a brick type transition at the roof, from large cinder type blocks to appearance bricks.

FWIW if I had to do it like you did, and this is ONLY in HINDSIGHT, I would go with four of the strap sets etc, 2 high 2 low, each pair sharing the load.

It will be informative to examine the failure point when it becomes available for scrutiny.

Oh, and GREAT pictures......

outlawmws · Mar 1, 2006

Well from the Pic, its obvious the strap failed, or if sliding clips were used at both ends, the clip may have come off or failed.

20-20 hindsight, is you should move the angle on the "long" side(s) of the chimny upwards, or use longer angle on that side, and increase the distance between the straps. it appears that they have only about a foot separating them, and that gives a lot of leverage for the antenna assembly to stress the straps. you look to have maybe 18" or so and this will dramatically lower the loads on the straps.

I'm about to mount an antenna or two on my second story addition (No chimney, so I'll be mounting to the wall), so this has given me some guidance for spreading that load (My town gets strong winds most any day off the bay)

Sandy G · Mar 1, 2006

Well, at least it looks like the Winegard is salvageable. Whitehall, no disrespect intended, but maybe you oughta ask around, & get a pro to put this puppy back up-Looks to me like you did a good job, but it STILL came down...With the wind you guys get there, maybe a savvy carpenter would know a few tricks to keep an antenna up. Just my .02 worth...and I CERTAINLY am NOT trying to make you mad...-Sandy G.

markthefixer · Mar 1, 2006

Well FWIW I took a picture of my 14 year old tv installation, on the wall.

Yes that mast is doubled up, two side by side. When my brother lived here he had a 5/8 wave CB antenna installed OVER the tv antenna. I'm not sure which was the worst wind load, your winegard, or that tall (18 foot?) fiberglass antenna. When the wind blew hard, talk about FLEXING, we NEEDED that doubled mast.

And yes the antenna elements for the lower longer channels are beat to #$%, by a neighbors tree branch that grew over. The bonging of the tree branch on the CB antenna during a windstorm was quite audible in the house.They recently chopped the tree branch off on the other side of the property line. I was a little nervous when they did it, as there was a large first floor window, and my A/C condenser in the line of fire (fall?). They missed.

And when I took the picture I noticed that the aluminum (what WAS I thinking??) wire from the ground block to the in-ground rod was corroded off on the bottom side of the ground block. IT WAS a pass through arrangement starting from from the mast, through the ground block without a break (originally) to the ground rod.

Whitehall · Mar 1, 2006

I separated the straps as far apart as possible given the angle of the roof. Looking at the photos in detail, I now suspect that the strap clamp failed rather than the strap metal. This is the little part that clamps the strap onto itself after it passes through the threaded attachment eye.

The remedy will be to use a better crimping tool on the replacement straps (and better workmanship!)

Besides, winter is almost over and by the time I get to repair it, the likelihood of strong storms will be reduced. Given our California climate, it will be November before I have to worry.

EddyR · Mar 1, 2006

Whirehall I put up tv antenna's for 30 years and on the bigger ones I uses Ham gear. It is a lot thicker material.I also sometimes used two straps on each bracket. I have never seen the mast bracket fail as yours did.
Ed

outlawmws · Mar 1, 2006

Whitehall said:
I separated the straps as far apart as possible given the angle of the roof. SNIP.

From your photo, it looks like the top strap can be moved up at least 6". Not so? All it should need is the outboard angle moved up.

Whitehall · Mar 1, 2006

Not so, as installed. The top strap and the angles slipped when the top strap broke.

Whitehall · Mar 12, 2006

Finally got up there and fixed it.

Turns out that the metal standoff pieces just twisted under the loads! The straps and clamps were fine.

Installed a new set with a bit better craftsmanship, having learned a thing or two from the previous effort. It will be a little stronger but not much. Hopefully, we've had our strongest winds of the seasons so I've got time for improvements or to chop some of the mast off to shorten it.

Whitehall · Jun 9, 2006

Here's photos of the metal brackets that connected the straps to the mast. Hope you can see the deformation. :tears:

Antenna Down

Super Member

Super Member

Retired Member

Honky Tonk Hero

On the Run

Addicted Member

On Hiatus, hospitalized and NOT doing Clutches

Super Member

Attachments

Active Member

Super Member

On Hiatus, hospitalized and NOT doing Clutches

On the Run

Retired Member

On Hiatus, hospitalized and NOT doing Clutches

Attachments

Super Member

Well-Known Member

On the Run

Super Member

Super Member

Super Member

Attachments