Batboard

How the hell do I calculate the frequency of these types of antennas from the measurements of the dipole elements? I tried calculating the measurement from the "hot" side of the feedpoint to the top of the "loop" on an antenna who's frequency is known as a 1/4 wave, and that comes up around 30 MHz off. I next tried measuring from the hot side of the feedpoint all the way around the top of the loop, back to the center support and calculating as a 1/2 wave, and that comes up around 20 MHz off. I then tried measuring from the hot side of the feedpoint all the way around the loop, and calculating as a full-wave loop, and still came up around 20 MHz off. How do I get an accurate calculation? If it matters, what I actually need to calculate is a low band dipole of the same type.

You need to measure the distance between the elements
The diameter of the tube.
All actual calculations relate from the centre of the tube.
So to get an acurate lemght measure the outside of the loop.
measure the inside of the loop.
subtract the inside from the ourside.
Divide it by 2 and add it to the inside.
Thats possibly where your frequency is going.

I should add that the phasing harness will not work as they will be the wrong impedence