[TowerTalk] Antenna traps

[jcjacobsen]

John, KK9A wrote:

Jim, are these fan dipoles?  I am not understanding how a loading coils will
make a dipole work on two bands.

John KK9A


John and others:


I've made MANY wire antennas using coils. In simple terms (which I can understand) what happens is, say an 80/40 dipole, the coils is made/wound with enough turns so on 40 it has a high enough inductive reactance to block rf flow any father. On 80 the coil acts as a plain load coil 


W9INN used these properties on his wire antennas, even multi band (more than 2 bands). Yes bandwidth suffers on lower bands, but that's what they make antenna "tuners" for.


I believe Butternut uses something similar on their HF6/9V, HF2V, and with the 160 kit for same.


Hope this helps.
73 and stay well
K9WN Jake


PS: NOT an antenna Guru. Much to old for heavy thoughts like this.