QRP Antennas – W9TH.com

August 31, 2021 Jeff

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

July 16, 2019 Jeff

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

July 4, 2019 Jeff

QRP Guys End Fed Half Wave Antenna – Part 2

I found some stranded, silver plated #22 wire that has Teflon insulation. It’s not copper-weld, but it’s tough stuff. I attached a 63 foot piece, and wrapped it around the PCB. According to the chart, the wire should be 61’6″, so I will have to trim the antenna for best SWR on site.

June 11, 2019 Jeff

QRP Guys No Tune End Fed Half Wave Antenna

Just finished building the kit. The instructions and illustrations were very good and easy to follow. Assembly took less than an hour. I will be using this antenna on our yearly cabin trip coming up in July 2019. I will do some testing before then and publish the results.