Re: LF Hoop Loop built

Steve Ratzlaff <steveratz@...>

Hi Farmerik,
Not much chance of an article with pictures from me, but Jim Kearman's webpage has a good article about the MW version, maybe some info on the LW version too.
I could supply a transformer for both MW and/or LW versions, contact me for details if interested. However, either would be for a specific 23 inch diameter loop wound with 5 spaced turns, as that's what I'm using. The transformers are specific to the particular loop size and turns in order to resonate over the same tuning range.
NE Oregon

----- Original Message -----
From: "farmerik" <>
To: <>
Sent: Friday, July 09, 2010 2:07 PM
Subject: [ultralightdx] Re: LF Hoop Loop built

Any chance you will write this up as an article with pictures? How about custom winding a transformer? - FARMERIK

--- In, "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 LC meter.
NE Oregon


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