Just looked out back.

[N3DRB The Derb]

Yep antenna down again. 

I just wanna leave it down for now. Conditions have been so rotten lately and hardly anyones on anyway. I'll work on the junk and get that end going.

[kb3ouk]

Been too wet up here lately to do anything, can't bale hay or do anything outside because of the stinkn rain. It started out foggy this morning but cleared up so that we could unload some wagons, but it's still humid, which I think is worst than when the temp is in the 90s and the air is dry, which I haven'tseen around heer in a while.

[Tom WA3KLR]

My yard is so soggy that just using the rotary push mower left ugly ruts.

[Pete, WA2CWA]

My yard is so soggy that my dogs carry their own towels.

[w3jn]

I can't believe it    Which end came down?

[K1JJ]

I'm surprised to hear that, Derb. Yes, what failed?

I assume you're using aircraft cable for the end supports now.  If it was the flat-top dipole itself that failed, why not make the flat top AND the end supports outa 3/16" aircraft cable? The darn trees would fall down first before it wud fail again. The RF loss using steel cable that diameter is insignificant with a dipole on 75M.

You can interface steel cable to copper feeders using those heavy silver plated clamp-on/solder lugs. Put a set of lugs on the feeders too and bolt and solder them together, including the steel wire. Steel willl solder to silver plated lugs.  Tape up the connections and cover with RTV for a good seal.


Use doubled or tripled paralleled insulators for more strength.

That flat top will be as strong as Godzirra.

This may be the only way to keep the antenna up since it's not supported at the center.

Wish I lived closer, OM.

T

[N3DRB The Derb]

Same end as last 3 times - the one going out into the field. I have'nt looked yet to see if the end wire pulled out like last time, or the wire itself broke. I tried to talk to Tron because Deano was on and I wanted him to relay a hay buddy to deano. I got the " I hear a piss weaker on the channel" comeback, and I knew right then something was up. saw the center insulator laying on the back deck this morning. gay. 

Gonna have to come up with something new I think. This is getting to be a 2X annual ritual. 

[Tom WA3KLR]

Yer missin' the West Virginnie QSO party Derb.

[N3DRB The Derb]

hauled the wire inside the fence. broke where the wire meets the end insulator. This time the wire actually broke instead of just getting unraveled.

Glo and I talking about other antenna options so this wont keep happening over and over year after year. Might make up a KB3AHE Special and hang it between 2 RS 36'ft tall push up masts. or possibly a 15' high roof tower. She's ok with anything. 

 

[WA1GFZ]

Derb,
It sounds like you are pulling it up too tight,

[k4kyv]

Are you using stranded copper antenna wire?  I  had the same problem years ago with the stuff.  It seems very prone to metal fatigue, and would break off right where it was twisted together.  If you make a solder connection it is even worse, and will last less than half the time compared to just twisting it.

I have had much better results with #10 and #8 (solid) copperweld.  I have never had a piece of it to break.  One thing, I always make sure the "live end" of the wire, i.e. the antenna wire with tension on it,  goes directly to the insulator with no bends or twists until it reaches the eye of the insulator.  The "dead end", the end of the wire that passes through the insulator, is twisted round the live wire.  I have a little tool that was designed for twisting electric fence wire, that I modified to accommodate the larger wire.  Vice grips will also work.

I found the #8 a PITA to twist, so now I prefer to use split copper bolts, the things designed for splicing copper electrical wires.  I bend the dead end of the wire back after inserting it through the eye of the insulator and form it to fit snugly against the the live end, then attach three split bolts, spaced  2 or 3 inches apart, to  hold the dead end in place.  The wire is so stiff that it would never pull through the insulator; the insulator would break in two long before.  That's exactly what happend several times last winter during the ice storm and high winds that kept dropping trees and branches on the beverage.

You can let one of the split bolts on each side serve double duty for attaching the feeders to the legs of the dipole.

Solid copper will also work, but I have found  that it stretches.  Maybe hard-drawn  would work if you can find it.  Don't use "copper clad" electric fence wire.  It has a microscopically thin layer of copper deposited on the steel, and  tends to rust through in a short time.  Even considering the skin effect, the copper coating probably isn't thick enough to carry much of the rf current.

[W9GT]

Try using a spring or a bungie in series with one or both end supporting ropes/wires.  Sounds like the wind might be blowing the tree or other support around enough to break the wire.  Also you could use a weight on the end of a rope passing thru a pulley on one or both ends.  The weight keeps the antenna taught and moves up and down as the end supports sway in the breeze.  Also #12 stranded heavy insulated house (THHN?) wire works really great for  'tennas and can be purchased at your local Home Despot.  I hear the price has come down recently also.

73,  Jack, W9GT

[WD8BIL]

The window weight setup works great for me derb. Tie off one end and hang a weight (bucket o' rocks) off the other end. When the trees sway you can watch the weight go uuupppp and doowwwwn!

[k4kyv]

Or else use wire strong enough that it keeps the tree limbs in check.

[K1JJ]

As I posted above, make the WHOLE span, including the flat top and end support wire, out of 3/16" aircraft cable available at Home Despot.  It will NEVER break again.

T

[w3jn]

There was plenty of slack in it, wasn't pulled tight at all.

Most of the support rope on that end was aircraft cable.  The ant itself is a W7FG.

The last time it failed the support rope pulled thru the PVC insulator.  Made sure that wouldn't happen again.  I fail to see what's putting such stress on that antenner though 

[N3DRB The Derb]

It was not tight at all. there was probably 20 ft of slack in the middle. Those trees in the back field swish back and forth 30 ft at the top branches in a good windstorm. I have 1 good antenna tree in my yard. Gotta get another end support on my property. I've never been too comfy about stringing the ant outside the yard.

It's just a waste of time to put it up again until I get some new skyhook infrastructure in place. Time to rethink and figure something new.

I have a problem with non copper stuff..I know Tom Vu speak truth, just my hangup... I think the W7FG wire is great for the down-lead, but not good for the antenna flat top itself. that wire is too light duty for my tastes. the feeders are great, but the next one that goes up will b using much heavier wire and some better insulators. Not a fan of the PVC for those.

Actually, I might just homebrew the next pair of antennas ( yeah, pair. I want a dedicated 40 meter antenna this time) and switch them with the old buzzard TV7-/U knife switch Phred gave me.

i think I can make better antennas than I can buy. So there.  Phhhhpppppttttt. 

[K1JJ]

How about some of that solid #8 copper wire at Home Despot for the flat top?   

Also, try a moving weight and pulley as already suggested, but use aircraft cable thru the active pulley. I once tried it with rope, and with a big load, the rope frayed and broke within a few days in the wind.

Between those two techniques and using strong ceramic insulators, it shud work FB.


T

[N3DRB The Derb]

yeh, I got a shiznit load of HQ silver solder, 52% silver, and I need to use it. Stuff is like 300% stronger than regular solder is. I have 20 feet of it.  made mistake when I ordered it - meant to order 20 inches. What a rube. 

I dont have any really stout ceramic insulators. I do have some really old buzzard pyrex glass ones, about 2 inches around and 6 inches long. Things are HUGE.

I'm going to Home Depot later today. Gonna get the wire. whatt'a ya think about the glass?  they're REALLY big. I'll take a pic later this morning.

[WD8BIL]

At the cabin I use 15ga electric fence wire. Regardless of what the purists say, it works great and ain't broke in 12 years. 1/4 mile for $8.

[flintstone mop]

Tim
I'm wondering if you live in a location where there is a steady wind and the trees picked sway a lot? My Previous location was full of oak trees about 90 feet high and there was very little sway. It would take thunder storm activity or hurricane force winds to get them moving excessively. I had three dipoles up and never a failure.
Steve recommended the aircraft wire and I only used that on one of the dipoles. Very expensive!
Fred