Total posts : 45366
The coil losses you reported are much too low. In practice, it is very difficult to get a loading coil Q higher than about 350, or so. The highest Q I have ever measured on a coil of any kind is about 600. I have measured thousands of coils.
First of all, it is practically impossible to calculate coil Q. The major causes of coil loss are the skin effect and the proximity effect. Skin effect is relatively easy to deal with, but no accurate formulas presently exist for the proximity effect. Terman’s handbook has formulas by Butterwoth, but these formulas are inaccurate. I have found from actual measurements that the Butterworth formulas greatly underestimate the proximity effect.
I am presently studying loading coils, and I will be posting in the future on Radio Joe’s loading coil thread.