On Mar 19, 6:49*pm, RHF wrote:
On Mar 19, 5:19*pm, bpnjensen wrote:









Today, in anticipation of a pretty substantial windstorm tonight, I
decided to add the next piece of the new antenna puzzle - this time,
the structural counterweight. *Tugging on the antenna line, I figured
it might need upwards of 15 pounds to hold it in place without much
sag - so I grabbed a gallon jug filled with water and went up to the
rope, just to get it started. *I did not bother to get out the
calculator and physics book to try to predict it ;-)

Lo and behold, I placed the jug on the support rope and it was too
much weight. *It kept that wire nearly horizontal, suggesting that the
tension was pretty high. *I would up leaving about 5 pints/pounds
water in the jug, and I may even empty a bit more.

So - it doesn't take much counterweight to hold up 65 feet of 14 gauge
stranded insulated wire with an acceptable sag. And now, let the wind
blow!

Just for future reference :-)

BpnJ,

Roughly 65 Feet of 14 AWG Stranded Insulated Wire
is 1.6 Pounds -so- 3X = 4.8 Pounds [5 Lbs] should do
as a Counter-Weight for the Antenna Wire.
[~25 Lbs per 1000 Feet of #14 AWG]

One US Gallon of Water is ~ 8.3 Pounds
-or- ~ 2 Pounds per Quart & 1 Pound per Pinthttp://wiki.answers.com/Q/How_much_does_one_gallon_of_water_weigh

A One Foot 'Sag' per 100 Feet Span is not bad {OK}
-no-sag-is-better-no-sag-is-better-no-sag-is-better-

Realistically -if- You have Good Quality Antenna Rigging
'Anchor' Hardware that is Installed Properly at each end :
Plus Good 1/8" Poly Rope = Breaking strength 200+ Lbs.
And *Good #14 Antenna Wire = Breaking strength 200+ Lbs.
-therefore-an- Antenna Counter-Weight @ 10% could
easily and Safely be ~20 Lbs {Tight with NO Sag}

TIP : The Less the Antenna Wire 'Sags' : The Less It Moves
in-the-air with the wind and elements; and that is Less Wear
at the Ends {Rigging Points} Due to Movement on the Ends.
-no-sag-is-good-no-sag-is-good-no-sag-is-good-no-sag-is-good-

Antenna Wire see Item # 541 herehttp://www.thewireman.com/antennap.html

Poly Antenna Rigging Rope see Item # 814 herehttp://www.thewireman.com/antacc.html

(o: *If You take another Look at that Sagging-Down
Antenna Wire when there is a Full Moon Directly
Overhead : You May Notice It Is Sagging-Up ;;-}}
nitt? ~ RHF
*.
*.
SWL Newbies : Matching the Antenna Ballast
Weight to the Wire Antenna Elementhttp://groups.google.com/group/rec.radio.shortwave/msg/4289a54e1646d5b2
*.
*.

I'm a lot more worried about the fact that my treetops can sway up to
about 5 feet in a windstorm, meaning a lot more than 20 lbs tension
on that wire. A little sag (like about 1 foot) along with the
pulleyed counterweight seems prudent to me. I could be talked out of
this, but I think a snapping wire is definitely in the cards.