High rise antenna?


#1

Thinking out-loud here… how can I go above the close-by obstacles?

I don’t think climbing on top of a 50 meter (150 ft) tree, at my age, will be beneficial for my health. I could pay somebody…

I also know that there are helium balloons capable of supporting antennas and other working apparatus for short amounts of time. But that’s not lasting a very long time.

I was contemplating to tether a drone… with the power cable (like CAT-5E) feeding the Pi+dongle+antenna. It would be some 4 lbs (close to 2kg). No need for batteries, but the cable can be heavy for 200’. For voltage drop reasons it will have to be fed with 9V and regulated up there to 5V. Data connection via WiFi. Anchored in triangle with nylon strings.

Not sure if the neighbors, wife or… FAA will like it though (they have regulations for drones, and for captive balloons, but not for captive drones), or how expensive would be, especially with that lifting capability. And 6 motor drones might be more than I would like to pay.


#2

Most consumer drones will have a relatively short airtime. 50m CAT5 cable will weigh approximately 1.5kg, a 15.000mAH powerbank weighs < 1/2kg. My guess is that powering with a powerbank and let the drone cruise at 50m until it needs to refuel would be your best option. Recently saw a DJI which even in shifting and gusting winds remained in position. If you want it captive: Use 1 or 1.4mm Dyneema kiteline, weight 0.067kg/100m.

However, try to the local firedepartment to help you get up to the top of the tree as that will give you a stable mounting place which could be constantly powered. Remember: The tree will get taller but the antenna will not go up with it :sunglasses:


#3

I’m betting that the duty cycle on a drone motor is not a 24 x 7 type of thing,so I’d wear a helmet in case it suddenly falls from the sky.

I have some tempting trees as well but likewise am not up to the climb and certainly am not at all interested in doing it again and again to maintain the system. You’d have to have some type of hoist system that would let you winch up and down like those tall parking lot or highway lighting poles. Assuming that could be solved, then you have 150 plus feet of dangling wire to sail in the wind and try to wreck everything each time the wind blows. And at my place squirrels and other critters would chew on it. :chipmunk:

I suppose if I was very patient I could mount an antenna on a young sapling and wait for it to grow taller, periodically feeding it more cable…:grin:


#4

The wiring would be just to power it up, actual data connection will be over WiFi like now. I can imagine some 24V power being sent with thinner wires than the CAT5E.
Motor duty is related to the actual power required from it. If you don’t go to the max, you can use them 100%. But again, that means extra motors - you pay either way.

Also, maybe I don’t need to actually climb on the tree… Shoot a rope line with my bow, over the top most V branch, then pull up an antenna (on top of PVC tube) with ballast weight on bottom (and the Receiver + Pi). Power feed with the same CAT5E cable.
That might be cheaper… But I need to wait for the fall because of the leafs being in the way now.

PS: This is awesome: https://www.youtube.com/watch?v=taLqFCUdxqs


#5

have you considered anchored kites like the japanese ones ?


#6

My area does not have a constant breeze to keep those afloat. Right now is dead calm.

I think I will try to get a rope over the top of a tree… cheapest way.


#7

You sound very patriotic, so I am sure the neighbours would not mind if you installed a 150ft ground tethered flagpole…


#8

Well, my first try is a failure :slight_smile:
I have bought a thin monofilament (fishing line) - 0.185mm dia. Tape it on one of my kid’s bow arrows. The bow is less than 20 lbs pull force (legal to shoot in my city limits).
Hint - unspool firstly a bunch of line on the ground. When re-trying, detach the line from the arrow, don’t try to pull back the arrow trough the branches/leafs.

I can’t shoot higher than 1/2 of my tree leafy crown :frowning.
I need a different method to cast that line. Bigger bow? Fishing rod?

The “tools”:


The “enemy”:


#9

The arrow appears lightweight, that may be part of the problem. I would put the wire close to the tree so the arrow does not have to pull the wire but only lift it.

Then again: May be use a slingshot, however only do so when the neighbours behind the tree are out of town. You will need mass to get everyghting across the tree AND also to come down at the other side - will need mass for that as well.

But, as you have been talking drones: Put the line over the top of the tree with the drone.

Not sure though why you would pick below the top of the tree as an antenna location. GHz frequencies are attenuated by almost everything, especially wet leaves.

I wish you wisdom!


#10

I am trying to get it above the mass of the leafs and above the surrounding trees. As of now I have one side that gets only the high-flinging planes (like a “forest” at less than 1/2 mile away).
Luckily that side doesn’t have that much traffic (it over the Ocean), but I think that… higher is better anyway. Right now I have the antenna a few feet above the rooftop.

My plan is to put the antenna on top of a 10’ PVC stick, with a counter weight in the other end, and raise that in the tree top (tied in middle). Don’t know exactly the mechanics, but I hope that 1/2 of that stick to raise above leaves.

Alternately, I can tie a cord from the tree top to the top of my house and lift the antenna there, at something like halfway height.

In the fall will be much better… when all the leaves are on the grass.


radial_fa radial_fr24


#11

I gotta believe it will be much easier to see what you are up against once the leaves are down. I have about twice the tree cover to deal with, many are pines that don’t lose their leaves in winter. Getting the mass to come down on the other side without snagging will be tricky !

Be interesting to see how the added height vs cable loss works out if you are able to get it up there.( I forget if you plan to put an LNA up with POE power)

Found these:
https://www.wirecare.com/manufacturer/lsdi/lsdi-tools/lsdi-wire-pulling-tools/ls85-202-sling-a-line-span-caster?gclid=EAIaIQobChMImbves_u33QIVSkwNCh2ZpQg6EAQYBCABEgKSLPD_BwE

To up the ante ( litterally :grinning:)
https://www.rocknrescue.com/product/naval-company-bridger-line-gun-kit/?dfw_tracker=31102-CGMODEL85&gclid=EAIaIQobChMImbves_u33QIVSkwNCh2ZpQg6EAQYAiABEgK_E_D_BwE


#12

I am considering putting the Pi up there too. Wi-Fi connection to my router. This way I just need to send two DC wires up there, with a small, local, switched mode power regulator. I ordered one already on ebay.
The slingshot might work. Especially this one:


#13

I’d build a tree platform on your biggest tree. From there you could mount a mast to the top and put any electronics you wanted. You could either attach a rope ladder or rent the cherry picker you used to build it in the first place.

They build them here all the time for kids. One place at the lake actually built a treehouse they rent to tourists…LOL


#14

Yeah… No.
I can’t justify that level of expense and effort :rofl:


#15

How do you like this highrise antenna? :wink:

Just installed it today. Quite a bit better reception compared to the attic, mostly from Northwest to Southwest because there are low hills to the North and higher hills to the East and South. Also the chimney you see in the picture was always in the way looking directly West.
The extra meter in height probably also helps because i have some houses on the other side of the street that are maybe 1 meter higher than our house. Not sure if the antenna really tops them now but i don’t feel like putting a mast on the house.

Oh the spider is a N connector that was included in the sdr pigtail set with a hose clamp holding the radials tight :slight_smile:


#16

Duct tape, nice.
Won’t cut it here but hey works for you!


#17

It’s really zoomed in on the picture. With the naked eye you can barely see it.

Also fully expect the construction to fail in a year or so :wink:
Just didn’t want to drill into the metal chimney shroud.


#18

The tape will probably fail before the clamps. You could solve that by using a couple of cable ties (ty-raps).


#19

SoNic67, google Bow Hunt Tree stand. Place that as high as possible and then mount your water proof box at this location to house the electronics. This will give you a safe place to stand and work. Extend your antenna from this location.
Leave the climbing pegs in place and remove just the bottom few to prevent “unauthorized” people from climbing up there.
Be safe and wear a safety harness when up there. Many a bow hunter got injured not doing so.

Regards

Dries


#20

Tree stand… it’s not tall enough. I have the antenna above my house roof ridge now. That’s already some 20’, like a tree stand.
I want to be all the way up there.