Dave's J-Pole Antenna Calculator

Enter your desired frequency and get the calculated lengths from below. For example, if you wanted a general J-Pole for 2 meters, you might enter the center of the 2 meter band which would be 146.00 mhz. If you predominately used the upper side of the 2 meter band you might put 147.00 mhz. Or if you mostly are on one repeater you might put that frequency, for example 147.12. Your antenna will be tuned to work optimally on the frequency you enter and will generally perform well within an entire band.

Optimal Frequency in Mhz: 
Show Measurements in:   Feet    Inches    Meters    Centimeters

Note: The measurement arrows are specifically drawn to point to EXACTLY where the measurements are from. For example, the distnace shown between the center poles is measured from pole to pole and NOT from center to center.

The four critical measurements are (from Left to Right):
    1. Long Arm Length
    2. Distance between Arms
    3. Distance of Feed Point from Base
    4. Short Arm Length

In case you didn't figure it out yourself - This drawing is NOT to scale.
<== The length of this lower portion doesn't really matter