Technical Info
Slim Jim Design
Slim Jim Antennas incorporate an end fed folded half wave dipole and a quarter wave J integrated matching system. Together these elements create an antenna that requires no grounding or ground plane to operate.
Enter the Dual Band Slim Jim
Building on the initial design of the slim jim we added traps that allow proper 70cm operation. Without these traps the folded dipole offers little to no resonance on 70cm. The antenna however yields only j-pole gain on 70cm.
Rigid Mounting
Though you may be tempted to insert the antenna into PVC or other plastic pipe, please understand that even plastic will affect the velocity factor of the antenna. We have found that zip tying the antenna to a quarter inch fiberglass mast is acceptable.
Resonance on 2m
The antennas have a reasonable amount of bandwidth offering a great match to the 2 meter band.
Resonance on 70cm
With the addition of the traps in the dual band models, great resonance is also afforded on the 70cm band.
Be Creative
Many of our customers have used creative mounting methods to suspend their antennas. As long as the antenna has a couple inches of clearance from solid material you should be fine.
More Info
Technical Specs
- Omni-directional pattern
- Rated to handle up to 100 watts
- Antenna fully weatherproof
- Portable
- Base antenna performance
- Quality connectors
- Durable RG-58a/u cable
- High strength ladder wire
- Dual band antennas feature trapped section for proper UHF alignment
- Ferrite choke balun installed on cable
FAQ's
A: While you are free to do as you wish with the product it is highly discouraged, as the pipe will degrade the tune of the antenna.
A: Through exhaustive testing we found there is no need to do this. There is also no downside to sealing the exposed wire portions. We do not do it to help keep the antennas as affordable as possible.
A: Yes, and if you look at the design outline above you will see why it exists between the radiator and matching section.
A: The antenna can be used in any position. I do not guarantee the best pattern when upside down, however customers have testified that it still works well. Horizontal positioning will only yield good results if the antennas on both ends are horizontal. Remember repeaters will always be on vertical antennas. In a horizontal plane the antenna will exhibit a pattern much like a dipole, not omni-directional as when mounted vertically.