Tweaker Stick 2

This version came about after looking at the maths and playing with different dimensions of materials for Tweaker Stick 1. I've realised that the PVC pipe will not support much more weight than it does now for the simple helical at 6m. This meant using really thick copper wire to improve power handling and bandwidth etc is out. The design has it's limitations and this was always expected.

I started looking around for other materials that are non conductive. The issue that might surprise some is the weight of the copper wire when you go up in size from 2mm to 6 or 8. The weigh causes a lever effect when it's all up the top in the loading coil. This isn't an issue until the wind blows. The PVC pipe starts vibrating like a guitar string in heavy breezes. This is even when guyed at 3m levels.

This lead me to think about sticking a power pole in the ground and winding the helical onto it. After realising installation of the helical would be a pain in the butt. I scrapped it and decided to go with 6mm copper wire straight up. This would be a lot easier to attach when the pole is in the ground. It will make this design handle more power. It also will help with the bandwidth of the aerial too.

The part I wasn't expecting is how beneficial the right placing of the loading coil is. Most techs with a vertical mast of a given height will just base load it. This is because the coil is easy to get to down the bottom. There is also good reason for a single straight run of pipe with no joins, it's structurally better. Putting a coil part way up needs some form of insulator between the isolated pipe sections. That would make a weak point!

As mentioned above the big surprise was how much efficiency you get back if you do move the coil up. Given that a power pole is wood you could rap the wire around the pole itself (and that is the plan). The base loaded version of 10m of pipe is about 20% but moving the coil up to about 60% of the total height you get 37% efficiency. There is a point where moving the coil higher doesn't get any better. As a guess I'd say that's about the 7m mark on a 10 m pole.

When considered against the total money out laid for the larger sized pole & effort spent with councils, you would be better off getting approval for the Tweaker Stick 3 (The Tweaker "T" design). In comparison at the same 21m height above the ground you would get 91%. A proper 1/4 wave (44m tower) is 97%.

But if you can get a bigger pole in the ground and a blind eye from council. The higher is still better. A 16m power pole with the same idea will get you 49/52% efficiency. Then on a 21m pole comes in at 76% efficiency. Not bad!

Exactly how I'm going to attach to the pole remains to be seen as each pole is different. The aim is to "not" make this look like an aerial as much as we can! I want people to be able to look at it and not come to the obvious conclusion.

The idea to use power poles is because there is a "pole guy" in most places in Australia and they can drop them in for you for a little extra. Plus it fits the free standing rule (at least up to 10m poles). As mentioned above the "higher the better" still applies balanced off against the cost of the pole and council permits etc. Water pipe is cheaper but your power pole can hold other aerials too (like an STL yagi). The water pipe design can't be used for extra aerials without a lot of technical messing around and money!

There is now a further design called the Tweaker Stick 4 where it is basically the same idea but done PVC pipe & 2.5mm wire.