In this image you can see a hand-wound air-core coil on the right (on the left is a reference AirDux inductor): http://blog-imgs-54-origin.fc2.com/t/a/k/take103/201211241704430c4s.jpg
In the original source (in Japanese), you can see the winding procedure: http://take103.blog.fc2.com/blog-entry-70.html
. The idea is to wind the coil on a form wrapped in plastic wrap. Then, some sort of glue is used to hold the turns in place. Finally the inner coil form and the plastic wrap are removed. As you can see, the result has some unevenness in spacing and height, and also shows some twist that is introduced after removing it from the form.
I'm thinking of using a similar technique to make a larger coil for loading a short dipole. I'll adjust the coil dimensions so that the required inductance can be achieved in a "square" coil form factor (not too long and skinny, and also not too short and fat).
Do you think the pictured coil construction technique would be able to achieve a coil Q of 500 or more at 7 MHz, using 2mm-diameter copper wire?
I'm aware of another technique of using plastic grommet strips (http://www.eham.net/articles/23124
), but I can't seem to find a supplier for those grommet strips locally, so I need to find another method, like the above method using glue.