Antenna Winder for QRP

This is a re-imagining of lhdru's antenna winder, using a smaller transformer wound on a 2643625002 core and a BNC connector. I find that it works better as a 2:15 autotransformer. A 3:21 has too much reactance at 10 m, so the losses are very high. Cutting it to a 2 primary turns solves that problem and I find that 15 secondary turns (including the first two, it's an autotransformer) gives better matching across all bands. I use it with a 26 gauge copper coated stranded steel wire approximately 20 meters long so it works on 40 meters.