Question for you guys. What works better a spring or weight to keep the wire tight. Also how tight should the wire be?
Thanks
Steve
Thanks
Steve
End Fed Antennas
- Thread starter shirsch101
- Start date
I used very light 16 gauge aluminum electric fence wire on a 51 foot random end fed on a slope with the top attached to a large pine tree that move a lot in the wind. A section of chain was used as a weight 2 lb? Would see as much as 3 feet of movement on the rope in the pully. Go as light as possible, just enough to take most of the sag out of the wire.
I am planning on a 83 ft wire from vent pipe on roof of house to a 20ft 1.5 inch conduit pole with a pulley attached. I am going to use nylon rope through the pulley to either a spring or weight so movement from wind isn’t the problem just the heat and cold expansion would be
That sounds like a typical install. For that length of 14-12ga wire and a single pully, a weight of around 30lbs should be good.
How much of a distance would you suspend the weight off the ground??
Close to the ground so it doesn't kill anyone if it should fall. You should have adequate rope going upwards to the pully for wire or pole movement and the weight should be a few feet off the ground in case the rope or wire stretches a little over time.
Thanks for your help!!!
Guess it depends on what you are attaching too, A vent pipe and a steel poll will not have much movement so I would think a spring would work well too. In my case I was attaching to a smallish branch on a pine tree. I needed to keep it very light with a lot of space under the weight (about 5 feet) I just put the section of chain I used on the scale and it weighed 2LB, 1.9 Oz With it being 5 feet off the ground the chain seemed like a good idea in case I or somebody walked into it as it would not hurt much. With the very light aluminum electric fence wire I used the 2LB was enough. Copper wire is much heavier and will need more weight.
Another question how high should the end fed wire be off the ground?
This was posted in the receiving antennas section so you may find it not as important as if the antenna was going to be used to transmit on the HF ham bands.
For receiving I think you will find noise to be the biggest factor. For example an antenna mounted up nice and high but near power lines may pickup a lot more noise then one mounted low and farther away.
I say go with what you have to work with or against. For example in my case the only spot I had was with the fed end near the house and quite low (about 10 feet) and the other was up about 50 feet but the tree holding up the high end was near the backyard powerlines and I picked up a lot of noise. It did not work well!
For 40-10m or even 80-10m I think about 30-32ft horizontal off the ground is ideal. Why? Because that's the first 1/2 wave point in height at 20m giving a low takeoff angle for DX and for 10m it would be a full wavelength, also great for low takeoff angle. On 40m its a 1/4 wave high giving the most gain straight up for NVIS and its also a decent heigh on 80m for effective NVIS. I've worked coast to coast on both 80 and 40m with a horizontal antenna at 30ft so even though its great for NVIS you will still make DX contacts on those bands.
A little higher or lower will degrade the low takeoff angle on 20 and 10m. At about 65ft you will loose the NVIS properties on 40m but the higher bands will be better for DX. Everything is a tradeoff.
A little higher or lower will degrade the low takeoff angle on 20 and 10m. At about 65ft you will loose the NVIS properties on 40m but the higher bands will be better for DX. Everything is a tradeoff.
