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.
73,
Steve
NE Oregon

----- Original Message -----
From: "farmerik" <farmerik@cox.net>
To: <ultralightdx@yahoogroups.com>
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 ultralightdx@yahoogroups.com, "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.
73,
Steve
NE Oregon



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