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I wanted to make a QRP 49:1 autotransformer for my travel pack.
The previous builds made with FT240-43 were larger than I wanted or needed. Besides that, I was bored seeing the weather had shut me in. This time I used FT140-43. Instead of a 2/14 turns method, I went with 3/21 turns, both being 1:7 ratio, or 49:1.
With 3000 Ohms resistor (3×1k in series) it tested out really good in all the bands I want to use in the field. I will be tuning a wire soon.
I needed a box, and was out of those I prefer, so I fell back only my repurposing tendencies. I had 3 boxes of this style, and use only one.
2WR183_Homer
K5HBB

[ATTACH=full]43210[/ATTACH] [ATTACH=full]43211[/ATTACH] [ATTACH=full]43212[/ATTACH]

[QUOTE="HomerBB, post: 755641, member: 8569"] I wanted to make a QRP 49:1 autotransformer for my travel pack. The previous builds made with FT240-43 were larger than I wanted or needed. Besides that, I was bored seeing the weather had shut me in. This time I used FT140-43. Instead of a 2/14 turns method, I went with 3/21 turns, both being 1:7 ratio, or 49:1. With 3000 Ohms resistor (3×1k in series) it tested out really good in all the bands I want to use in the field. I will be tuning a wire soon. I needed a box, and was out of those I prefer, so I fell back only my repurposing tendencies. I had 3 boxes of this style, and use only one. 2WR183_Homer K5HBB [ATTACH=full]43210[/ATTACH] [ATTACH=full]43211[/ATTACH] [ATTACH=full]43212[/ATTACH] [/QUOTE]

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