MY 40 METER LAZY "H" ARRAY
My primary antenna array for the "southcars net" operation.
by NA4L Dave Newman
"You can see I stand behind my philosophy on wire antennas."
"Make them simple then Make them work ! !"
You must have two
identical lazy "h" antennas to complete this array!
(Lengths are a bit fuzzy in the graphic..email Dave for exact numbers)
The LAZY "H" antenna is a general type of antenna that is in the curtain array family. By placing TWO 1 wavelength dipoles in a plane that is at right angles to the direction of maximum radiation and keeping the proper in-phase current condition to each element, you can achieve a HIGH GAIN bi-directional antenna.
For a near omni-pattern, MY version of the LAZY "H" array needed TWO identical antennas. (See the diagram at the top of this page.)
One antenna is broadside North and South and one antenna is broadside East and West.
These antennas are fed AT THE SAME TIME using equal lengths of 450 ohm ladder line.
Again, all the feed lines MUST be of equal lengths and the proper in-phase condition to each element MUST be maintained.
This array has a TOTAL of eight (8) 1/2 wavelength active elements.
The main feed line to my shack for this array is 450 ohm ladder line.
I use a Palstar AT4K tuner to match the array.
According to EZNEC this configuration will give basically an omni-pattern with about 4 to 6 db of antenna gain.
The array is cut to operate at 7.251 Mhz, the SouthCars Net frequency.
With the feed method I am using, BOTTOM FEED, with one twist and an electrical 1/2 wavelength phase line, (61.7 feet) of 450 ohm ladder line this equals 360 or 0 degrees, which keeps the elements in-phase.
Using this feed method the array can be used ONLY on the 40 meter Ham band. As an added plus, this array is very quiet.
After experimenting with EZNEC, the height of the lowest dipole seems to effect the radiation coverage. With the low dipole at only 30 feet and the highest dipole at 90 feet, I am able to hear the "close in stations" AND ALSO "the distance stations."
This should be a GOOD antenna for Net Control Stations, because they can receive and transmit nearly 360 degrees at the same time....with antenna gain!
This array is supported on one 100 foot tower and the ends are supported by tall oak and pine trees.
NO antenna turning necessary with this array!
So if you have the room, build one and get on the air in style! 73 Dave!
For questions email Dave at imna4l AT embarqmail.com (Remove the "AT" and add @ no spaces)
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