I have used solid teflon on hf. It gave good result but the best is RF grade Nylon.
On Sat, Aug 20, 2022, 9:03 AM Mark - N7EKU <
n7eku@...> wrote:
The test would be to measure the Q of a solid 3d printed toroid vs a hollow form one,
I couldn't find any posts about that, are there some here?? G3YNH talks a lot about materials, but mostly relating to capacitors where it makes a big difference.? For formers he just quotes two amateurs who did some experiments on dowels vs PVC antenna loading coils.? I'm not sure I would discount anything at this point without doing serious measurements.? And remember, in measuring coil Q everything needs to be controlled, such as coil placement from nearby surfaces and objects for example.
Micrometals uses phenolic material for their VHF toroid cores yet according to the chart it is a poor choice.? I hardly think they would choose something that give poor coil Q when they could have chosen PS for example.
Another good test would be to purchase some phenolic cores (material 0) and then copy it on a 3D printer and make Q measurements.
73
