Nelson Antennas 2m rollup antenna review
Review of the smallest portable 2m antenna on the market producing full size dipole performance and stows into your pocket.
J-Pole
History, simulations, measurements and real experiences of the famous, or infamous, J-Pole antenna.
The J-Pole antenna is herewith fixed
For what it’s worth, the myths surrounding the J antenna have been sorted out resulting in an improved version.
Antenna radiator decoupling stub flub?
Measurements and analysis suggest why quarter-wave stubs fail to completely isolate radiator conductors on multi-band antennas including the popular rollup 2m/440 J-Pole products. Possible improvements are shown.
J-pole: Where a choke is no joke
Measurements reveal the effects of common mode current on the J antenna.
Finding facts of Fair-Rite Ferrites
Learning more about several ferrite compositions from the Fair-Rite manufacturer including where to buy them.
Where a choke chokes
I measure one example of a ferrite coax choke for response over frequency to understand its suitability for VHF and UHF.
J antenna and variations thereof
There are many ways to morph the basic J antenna into useful forms.
J Antenna Design Patent Grant
USD798847S1 showcases one more incremental step towards a J antenna that works with masts and feedlines.
Mast Mountable Antenna Patent Application
The “mast mountable antenna” patent application is now available to review and critique.
N9TAX 2m Slim Jim Antenna Review
Erroneous specs aside, the N9TAX VHF SlimJim antenna is an exemplary dipole.
Antenna pattern plots: Good intentions vs. good data
In the 21st century should we believe antenna graphical gain data based on hope and hearsay? J-pole antenna gain drawings are a common bad example.
SlimJIM and Antenna Gainflation
Understanding why SlimJIM antenna aficionados hype the gain in their marketing and discussions.
Slim Jim vs. Traditional J-pole Antenna
Real measurements of a Slim Jim antenna and traditional j-pole antenna reveal the truth about their respective gain and pattern.
Mast Mountable J-Pole Antenna
The J-Pole antenna’s long and storied design history is due for one more chapter to mitigate the longstanding mast current and reliability issues.
Have your J-Pole and ground it too
Tame the predictable mast currents found in any j-pole antenna grounding conductive mast using a simple stub. Shown is empirical evidence why this is a problem and a very simple solution all future grounded j-pole antennas should incorporate.
First SOTA Activation – Using VHF FM
My first journey to the mountains as SOTA activator was a success using minimalist VHF FM gear.
Improving the Super-J
The traditional collinear J-Pole, aka Super-J, improves the basic J-Pole. Are further improvements possible? By replacing the phasing stub with a simple coil, the answer is yes. The result is the Collinear J-Pole.
Hawksbill Mtn. APRS Appalachian Trail Test
The Northern Virginia team of Ham Radio operators and companion hikers manned Hawksbill Mountain for the 2011 Appalachian Trail Golden Packet event. Gear included a Kenwood D710 with Green Light Lab GPS, 2m Collinear J-Pole and a 70cm collinear J-Pole.
J-Pole Antenna – Should I ground it?
To function as intended, the J-Pole antenna needs RF electrical isolation from its mount. Here’s why and in technicolor no less.
Hiking, Hams and Hills – Station #6 of the AT Golden Packet
Hiking, ham radio, hills and a portable collinear J-Pole combine to make the Golden Packet Test a memorable event.
5/8 Wave J-Pole vs. 1/2 Wave J-Pole EZNEC Shootout
We examine if 5/8 Wave J-Poles are better than 1/2 Wave J-Poles.
Collinear 5/8 wave J-Pole vs. Collinear 1/2 wave J-Pole EZNEC Shootout
Another 5/8 J-Pole Design arranged as a Collinear… can it justify the complexity and extra materials?
2 Meter, 5/4 Wave Antenna Revealed
We remove the mystique surrounding the 5/4 wave antenna comparing center and end fed approaches. One conclusion is the end fed 5/4 wave antenna shows little promise as a vertical antenna for terrestrial use.