Amateur Radio Pages
updated November 2014
Web Site By W G Taylor - Created Using Serif WebPlus X6 - Copyright ©  All Rights Reserved
LF and MF Experiments etc - 21
March 2014
The Donut.
Having used the previous top load for a little while and played with a few ideas in my head I decided on the design shown here on this page. Of course this still has to meet the same criteria.
ie. Anti Starlings.

I have followed a similar pattern as such I have used the same flexible former coil (The Donut) placed around a large plastic disc. On the top of the disc there is a capacity hat of copper wire. The coil measures about 100uH, the diagram & photo’s below will show the design in more detail.

By The Way........Any plastic material used is always tested in a microwave oven as a loss test, if the sample stays cold after 1 minute at full power then I can be reasonably sure it is not a lossy material at RF.
LF & MF experiments 20

October 2014

Although they did work, the two previous attempts to create a fairly efficient compact top load failed to even come close to performing as well as the earlier top load**. So I have decided to return to that top load construction but to include some sort of “Anti Starling” arrangement.

I have placed two parallel nylon lines (fishing line) along each of the radial arms. These are raised above the radial supports by about 20 to 30 mm so as to make it difficult and/or uncomfortable for the Starlings to perch there. I have also done a similar arrangement above the perimeter wires.

I constructed the main top load supporting hardware as in the earlier design. I made and fitted 12 small “L” shaped PVC supports for the nylon lines (3 for each radial arm).

** LF and MF Experiments etc - 18

LF & MF experiments 22