Any chance you will write this up as an article with pictures? How about custom winding a transformer? - FARMERIK
toggle quoted messageShow quoted text
--- In firstname.lastname@example.org, "Steve Ratzlaff" <steveratz@...> wrote:
I built an LF version of the Hoop Loop today. I started with a larger FT140-61 toroid and after I got that working I wound a second transformer on a smaller FT114-61. There's quite a size and especially weight difference between them. The larger one had quite a bit of unwound core left; the smaller one is filled about 3/4, and the smaller one is easier to work with due to less size and weight. About 16 feet of wire is needed for the secondary, and use of a homemade wooden bobbin makes winding manageable, though not exactly fun.
A daytime check outside pulled in 9 NDBs, the most I've ever received during daytime on a portable radio with internal or small external loop antenna. I'll try it at night, and expect reception to be much better.
I used the same 23" diameter loop with 5 spaced turns as before when I wound the AMBC transformer. The secondary winding has 180 turns of #30 enamel wire on the smaller FT114-61 core with 14 centertapped turns for the primary. Tuning range is 165-810 kHz and loop and transformer together measure about 1750 uH on the aade.com LC meter.