QTY 10 for club project. This is a perfect Radio club project, simple, easy to build, good for learning, inexpensive and most importantly - USEFUL!
Bring your club together for a project they will love to build and use. This listing is for 10 kits.What if you need a different QTY (10 or more)? Want just one or two?
This is the KM4CFT End Fed QRP unun kit, very small 1 7/8"L x 5/8"W and very light (0.4 ounce)! Perfect for SOTA, POTA, backpacking or just seeing what you can work in a minimalist way. You build this kit to feed your EFHW (End Fed Half wave) or EFRW (End Fed random Wire) antenna. This antenna unun kit is designed to be built for one of the two types of end fed antennas described below.
The End Fed Half Wave (EFHW) is known as a resonant antenna. This means it is designed to be used. They are designed to be resonant on half wave multiples of its resonant.So an 80 meter EFHW is (theoretically) resonant on the 80, 40, 20, and 10 meter bands. Isn't completely true though since the bands aren't exactly multiples of each other. Can use a loading coil along the wire to bring other bands into resonance. Deployed in the same fashion as a dipole: sloper, inverted vee, or even vertical if you use a feedline. The End Fed Random Wire (EFRW) antenna is not resonant and is designed to be used with an antenna. The antenna is essentially designed to be equally "out of tune" on a large range of frequencies. Such that a tuner can be used to bring the antenna into a match, and therefore be usable on many bands.
This is a great option for radios that have a built-in ATU like the Elecraft KX2, KX3, KH1 and the. With this type of antenna, you want to prevent the antenna from being. Resonant on any particular band. For finding the length you want, I recommend looking at an article.That the University of Delaware posted. It can be easily found by doing an internet search for End fed.