ant. question

[stingray]

i have a clr2 and an antenna specialists mighty magnum 3.
the clr 2 is supposedly a 5/8 wave. it is 19 feet 10 inches.
how is this possible. the mighty magnum 3 is 18 feet and is half wave.
is hygain lying? i know both have some kind of coil so what makes the magnum stay at half wave and what makes the clr2 5/8 wave?

 

[W5LZ]

Good question. And the answer is where those coils are and what they are there for.
An end fed 1/2 wave antenna has a very high input impedance, something in the neighborhood of 2000 ohms or so. That means that the coil (which should be at the feed point) is an impedance matching device to make that 2000 ohms compatible to that 50 ohms feed line.
That Clr-2, should/could have two coils, or just one which is a combination of both loading coil (to make the thing seem like a 5/8 wave, just shorter) and impdance matching coil to make it's impedance closer to 50 ohms. The location for that loading coil isn't that exacting. It can be located almost anywhere up/down the vertical element. Or, it can be set right on top of that impedance matching coil, making both of them just separate parts of the same, larger, coil.
Make any sense to you?
- 'Doc