Engineering the EFHW 49:1 Transformer and Antenna

After doing the ferrite transformer scaling experiments last time, and learning a bit more about what matters in these transformers, it was time to make a stab at designing one. Let me review the salient observations from the previous work. 1) More primary turns and primary inductance improve the transformer efficiency and low end performance. [...]

Practical Antenna Modeling

Here are the slides for a presentation given to The Valley Radio Club on May 3, 2019. The hope is that the slides contain enough detail that the reader could easily build and run the examples in 4NEC2. Practical Antenna Modeling Power Point Presentation Practical Antenna Modeling PDF format slides Using the NEC Codes With Examples [...]

Antenna Comparisons using JT65 & JT9 Signals along with NEC Models

True understanding of a problem is confirmed when one can validate theoretical model predictions with measurements.  It is too easy to believe pretty pictures that modeling programs produce, especially when making meaningful measurements is so difficult.  In this article I try to take the bull by the horns and see how close I can come to [...]