Antennas for SOTA

Evaluating efficiency, transformer and mismatch losses in toroid transformers - some observations.

Two methods for transformer loss are evaluated. We learn that mismatch loss must be accounted for.

Toroid Transformers - How Hot Will It Get?

There are a number of factors in choosing a toroid for a RF transformer. While one may model electrical performance, calculate predicted...

Trapped 20/30/40 Meter EFHW Antenna

An End Fed Half Wave (EFHW) antenna for operation on 20, 30 and 40 meters was built for SOTA operation. By using traps, the antenna...

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End Fed Half Wave Antennas: More About the Primary Capacitor

I recently posted a blog claiming that a capacitor in the primary of the matching transformer is not needed for end fed half wave (EFHW)...

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End Fed Half Wave Antennas: Is a Primary Capacitor Really Needed?

In my research on End Fed Half Wave (EFHW) antennas I found that nearly all have a capacitor in the primary (rig) side of the transformer....

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