W9TH QRP Antenna Trap

QRP Antenna Traps

These traps were specifically desiged to use mini-ductor type coils. I had mini-ductor coil stock on hand, so I wanted a design that would be produce a higher Q trap than ones made with torroids. However, the design can easily be used with torroids. There is a mounting hole for use with a nylon screw to hold the torroid in place. Also, there are places to add multiple capacitors in parallel in case you needed a custom capacitance to achieve resonance for a particular band. The trap PCB can easily fit into a small pill bottle for weatherproofing. For temporary

Continue reading

QRP Guys End Fed Half Wave Antenna – Part 3

I didn’t have time to test the antenna before our cabin trip, so I took some measurements on-site. The antenna was strung between the upper deck of the cabin and a nearby tree. The wire I used was 63 feet long, I intended to cut it to length when the antenna was put up. What actually happened was I passed the end of the wire through a plastic dog bone insulator and wrapped it back on itself about a foot, and called it good. The SWR turned out to be so close to perfect, I didn’t make any adjustments. Here

Continue reading