Search Results for: arrl efhw kit

This article continues on from several articles that discussed the ARRL EFHW kit transformer, apparently made by hfkits.com, and the revised design at ARRL EFHW (hfkits.com) antenna kit transformer – revised design #1 – part 1. This article presents a saturation calculation. You will not often see saturation calcs (for reasons that will become apparent), … Continue reading ARRL EFHW (hfkits.com) antenna kit transformer – revised design #1 – part 2

This article continues on from several articles that discussed the ARRL EFHW kit transformer, apparently made by hfkits.com. This article presents a redesign of the transformer to address many of the issues that give rise to poor performance, and bench measurement of the prototype. Keep in mind that the end objective is an antenna SYSTEM … Continue reading ARRL EFHW (hfkits.com) antenna kit transformer – revised design #1 – part 1

Two previous articles were desk studies of the the ARRL EFHW kit transformer, apparently made by hfkits.com: Thoughts on the ARRL EFHW antenna kit transformer; and Thoughts on the ARRL EFHW antenna kit transformer – improvements? This article documents a build and bench measurement of the component transformer’s performance, but keep in mind that the … Continue reading ARRL EFHW (hfkits.com) antenna kit transformer – measurement

This is a follow up to Thoughts on the ARRL EFHW antenna kit transformer. The first point to note is that Amidon’s 43 product of recent years is specified identically to National Magnetics Group H material. It is significantly different to Fair-rite’s 43 mix. Though the parts list specifies an Amidon #43 core, I note … Continue reading Thoughts on the ARRL EFHW antenna kit transformer – improvements?

Several readers have asked my thoughts on the ARRL EFHW kit. I have not built and measured the thing, but have done the first step in a feasibility study. The transformer design is not novel, it is widely copied and this may be one of the copies. The design is usually published without any meaningful … Continue reading Thoughts on the ARRL EFHW antenna kit transformer

It seems that even a basic but sound understanding of transformers challenges lots of hams, and even online experts that have been heard to brag of their qualifications so as to intimidate others who might question their words. So at ARRL EFHW (hfkits.com) antenna kit transformer – revised design #1 – part 2 I estimated … Continue reading Transformers and magnetic saturation