HFU HF Underground

Technical Topics => Equipment => Topic started by: ChrisSmolinski on November 26, 2019, 1206 UTC

Title: How high is that antenna rope in the tree anyway?
Post by: ChrisSmolinski on November 26, 2019, 1206 UTC

I find it difficult to judge the height of a rope over a tree. Is it 60 feet, 80 feet?  My wife came up with a simple solution. Put some colored cable ties on the rope, evenly spaced, before you haul it up over the tree. I left the full length of the tie on the rope after pulling it snug. You can spot/count the ties and accurately estimate the height of the rope if it is vertical. I pulled the rope until there was a cable tie at the top, then counted how many were on the vertical rope run, and measured the remaining distance down, which is trivial to do at near ground level. No problems at all with the ties getting stuck on the way up or down.
 
I also found it handy when determining what the length of a new T2FD antenna I am working on should be. I spaced the tie wraps every 20 feet, ran the rope up the tree vertically, then down at the angle the T2FD will run. Turns out the height is 85 feet and I can fit a 120 foot T2FD.

Only took two tries with the Big Shot to get it over the tree: https://www.hfunderground.com/board/index.php/topic,60415.0.html (https://www.hfunderground.com/board/index.php/topic,60415.0.html)

Neon colored cable ties: https://www.amazon.com/LETON-Multi-Purpose-Sorted-Pieces-Length/dp/B07V8RX8QD?tag=blackcatsyste-20
 (https://www.amazon.com/LETON-Multi-Purpose-Sorted-Pieces-Length/dp/B07V8RX8QD?tag=blackcatsyste-20)


(https://i.imgur.com/Sk7SQLd.png)

Title: Re: How high is that antenna rope in the tree anyway?
Post by: NJQA on November 27, 2019, 1140 UTC

I think the zip ties would get tangled in the branches, leaving me with a piece of line that I can’t get up or down anymore. 

I have my wife stand at the base of a tree, holding a 10 foot piece of copper or PVC pipe vertically.  When I back away far enough, the 10 ft piece of pipe is used to guesstimate how tall the tree is.  This works reasonably well and is very quick.  For better accuracy I take a picture and then take the ratio of the pipe length to the tree length in the picture to get a more accurate estimate.

For best accuracy, back as far away as you can, while still being able to visually make out the pipe length.

Title: Re: How high is that antenna rope in the tree anyway?
Post by: pinto vortando on December 01, 2019, 1557 UTC

There is a simple method involving the use of a yardstick and a measuring tape based on similar triangles
for determining the height of a tree or any other object.
There is an even simpler "scout" method that requires only a stick.
No climbing or hauling anything up into the tree is necessary in either case.
Neither method is precise but will give a fairly close approximation.