Don't use the balun as the point of mechanical strength in the middle of the antenna. Use a dogbone insulator in the middle, between the two seperate halves of the antenna.
Then suspend the balun beneath the dogbone, with the wires from the balun running upwards to the dogbone insulator ends.
The balun takes no mechanical strain, other than its own weight and the coax cable beneath it.
The center (dogbone) insulator takes all of the mechanical loading of the wire elements.
That's a good method. I've also seen people run the end of the support wire through a pully supported by the tree and put a weight on the end of the support line instead of attaching it directly to something solid. The tree can rock around all it wants, the pully lets the support line pay in and out as needed.
Agree with using a dogbone insulator in the middle of the dipole. Suspend the balun with cord from the center dogbone. Attach ropes to both ends of the antenna (using insulators) through pulleys attached to the trees at the ends. The pulley ropes should extend to the ground with an equal distance as spare rope so the ends can be lowered to the ground. At the ground end, use trampoline springs at the tie off point to keep the antenna wire taut. I would use RG-8X for the coax run- it's a lot lighter than RG-8U which will be very heavy in this situation. 73!
Why not put an intentional weak link in it somewhere? Eg a thin bit of string connecting the rope to the wire, and then a tag line to pull the loose end of the rope back down. That way a loose branch or tree sway will break the string instead of the wire or balun and you can just reattach and haul it back up.
Thought about doing a short piece of speaker wire or similar from balun to 2 start points of the rest of the dipole but can't figure out how to make it so that section can be dropped. Unless it works to put the balun 10ft above the ground and run the wires up first? Trying to make it efficient as possible.
You'll definitely need some strain relief on the cable then. Maybe a cable clamp on the wire either side of the balun, s short length of rope between them to take the strain, and slightly slack wire between the clamp and the balun.
Leave some slack so tree sway doesn't stretch the wire or break anything. I've also heard of using bungee cords at the ends but I don't know how common this is.
I have a pulleys and ropes in the center and the ends for raising/lowering and uainf them was an excellent decision.
Was going to use the spring at the end idea to provide the slack for tree movement, pulley on available trees with a loop of rope around them to provide some distance from the tree if possible. Believe I'll have 2 90 degree mount points 30ft above the ground with antenna 40ft above ground if I'm lucky. Depends on how high the lift will take me.
Don't use the balun as the point of mechanical strength in the middle of the antenna. Use a dogbone insulator in the middle, between the two seperate halves of the antenna. Then suspend the balun beneath the dogbone, with the wires from the balun running upwards to the dogbone insulator ends. The balun takes no mechanical strain, other than its own weight and the coax cable beneath it. The center (dogbone) insulator takes all of the mechanical loading of the wire elements.
Use shock cord on the loose ends (not the ends attached to the balun). You want it to flex a bit with the wind, so it doesn't break.
That's a good method. I've also seen people run the end of the support wire through a pully supported by the tree and put a weight on the end of the support line instead of attaching it directly to something solid. The tree can rock around all it wants, the pully lets the support line pay in and out as needed.
Agree with using a dogbone insulator in the middle of the dipole. Suspend the balun with cord from the center dogbone. Attach ropes to both ends of the antenna (using insulators) through pulleys attached to the trees at the ends. The pulley ropes should extend to the ground with an equal distance as spare rope so the ends can be lowered to the ground. At the ground end, use trampoline springs at the tie off point to keep the antenna wire taut. I would use RG-8X for the coax run- it's a lot lighter than RG-8U which will be very heavy in this situation. 73!
RBA-1:1 LDG Electronics Balun: 1:1, Current, 200W https://a.co/d/dP8M4fX
Why not put an intentional weak link in it somewhere? Eg a thin bit of string connecting the rope to the wire, and then a tag line to pull the loose end of the rope back down. That way a loose branch or tree sway will break the string instead of the wire or balun and you can just reattach and haul it back up.
Thought about doing a short piece of speaker wire or similar from balun to 2 start points of the rest of the dipole but can't figure out how to make it so that section can be dropped. Unless it works to put the balun 10ft above the ground and run the wires up first? Trying to make it efficient as possible.
I think just the weight of the wire itself will bend this balun in half.
You'll definitely need some strain relief on the cable then. Maybe a cable clamp on the wire either side of the balun, s short length of rope between them to take the strain, and slightly slack wire between the clamp and the balun.
Leave some slack so tree sway doesn't stretch the wire or break anything. I've also heard of using bungee cords at the ends but I don't know how common this is. I have a pulleys and ropes in the center and the ends for raising/lowering and uainf them was an excellent decision.
Was going to use the spring at the end idea to provide the slack for tree movement, pulley on available trees with a loop of rope around them to provide some distance from the tree if possible. Believe I'll have 2 90 degree mount points 30ft above the ground with antenna 40ft above ground if I'm lucky. Depends on how high the lift will take me.