Thin James
![Picture](/uploads/1/6/9/6/16968694/5884966.jpg?133)
This design has been tested with 100W of transmit power. No problems are anticipated for powers up to 500W. The name Slim Jim comes from its slender construction and the use of a J type matching stub (J integrated match = JIM). The integrated balun means that the balanced dipole of the aerial is properly connected to the unbalanced co-axial feeder cable from the transmitter. If you don't use a balun, (for example if you connect your coax straight to a simple dipole), your coax turns into part of your aerial. This is bad as
- Transmit power is wasted by being radiated from the cable instead of the aerial
- Increased risk of your RF (radio frequency) power interfering with your audio circuitry in and connected to your transmitter, due to RF being radiated from the feeder cable near to your transmitter.