LPi - Wideband End-Fed Antenna


End-fed antennas are often more convenient to use than center-fed ones. The LPi antenna belongs to this category. And it has quite unique features. 

Firstly, it has a built-in counterpoise, and it means you do not need RF grounding or connect additional counterpoises. The coaxial cable braid does not act as a hidden counterpoise (as is the case with the EFHW antennas). 

Secondly, the antenna has an exceptionally large SWR bandwidth. Due to that, it is possible in many cases to cover not one but two and sometimes even three neighboring amateur HF bands. The prototype antenna presented in the second part of the article covers the frequency range 21–29.7 MHz, that is, it covers three bands (plus CB as a bonus). 

Thirdly, the LPi antenna is simple to build – you do not need any sophisticated tools or extensive construction experience.