On-line antenna designer. Calculate the required dimensions for a Slim Jim antenna construction for any given frequency.
Enter the required frequency in MHz and the antenna designer will calculate the dimensions of the elements as shown below.
The Slim Jim antenna is an extended version of the J-Pole antenna, using the same
matching stub principle. The length of the antenna is three quarter wavelength.
This antenna design does not need a ground plane and is ideal for mounting inside
PVC piping to protect it from the elements.
Performs very well and can be used for RX and TX purposes. It can be made from any
common household wiring.. The thicker the wire, the wider the bandwidth of the antenna
from its center frequency.
Frequency calculations are based on radio waves traveling at the speed of light
299 792 458 meters per second.
Side view: ADS-B Slim Jim
Front view: ADS-B Slim Jim
Above images show a Slim Jim built for 1090 MHz using this antenna calculator. Note the coax balan, this is needed to keep current from the antenna off the feed line.