A Super J-Pole Antenna for the 70Mhz (4m) Amateur band.
The Vortex ‘Super J-Pole’ Antenna consists of a five eighth wave vertical radiator, a half wave tuning section and a half wave top section. At the base, a quarter wave matching stub forms the classic ‘J Shape’. The addition of the extra half wave top section boosts the gain over a standard J-Pole. The Super J-Pole has an added advantage that tuning can be varied over a fairly wide frequency range by moving the feed-point location up or down. This also gives the user finer control over the impedance and match. The antenna is end fed and has an omni-directional radiation pattern and requires no ground plane or radials. The antenna has a nice low angle of radiation, typically 8 degrees when mounted at 4m in height. This angle reduces further the higher the antenna is mounted. A typical installation with the antenna at 8 meters above ground sees the angle reduce to 5 degrees and the gain increases to 7.29dbi when ground reflections are added….
Read Full Article: Link
Antenna
APARTMENT ANTENNA, HF, 40M-2M – MFJ-1622
The MFJ-1622 Apartment Antenna covers 40 through 2 Meters, mounts outdoor to windows, balconies, railings, and works great indoors mounted to d... Read more
HF Unity Gain Antenna Survey (#246)
“A Necessarily Incomplete Survey of Amateur Radio HF Unity Gain Antennas–a look at the many, many antennas used in ham radio that have abo... Read more
Building a Delta Loop Antenna For The 30m Band, Part 1.
“Since my 6m Delta Loop seems to work pretty well I decided to build one for the 30m band to be used with my Spiderbeam 12m mast. Unfortunately... Read more
Better Ground Radials for the Wolf River Coil
I demonstrate an improved ground radial system for the Wolf River Coil Silver Bullet 1000 Read more
Installing Wire Antennas in Trees
Installing Wire Antennas in trees Read Full Article: Read more
Tuning the Buddistick Pro Antenna
Designed as a multi-band, portable antenna for 40m – 6m, the Buddistick PRO™ is an excellent performer with any transceiver up to 250 watts.... Read more
Amateur Radio Tower Stand – KG0ZZ’s
A close up view of my ham radio tower and tower stand. The tower is five sections of Rohn 25-G tower. The top section is 8 feet long making the... Read more
Ham Radio EMP Kit, The Tactical Trash Can
“Many believe the worst threat to our electronics is being damaged by an Electromagnetic Pulse. Today I show you how to prevent that damage and... Read more
Review of Bilal Isotron 20m Single Band Antenna
More than one Oggie has suggested I review the Bilal Isotron 20m Single Band Antenna Solve Virtually Any Restricted Space Problem – 40 Meter Iso... Read more