HOWDY ! !
I AM A LOW BAND (40, 80, AND 160
METER) ANTENNA EXPERIMENTER
AND DXer ! !
F Y I>> I AM BUILDING A "mostly antennas" WEBSITE AT:
CHECK OUT THE "SHACK CAM" AT
" N A 4 L "
NORTH AMERICA 4 LIBERTY
MY PHILOSOPHY***"MAKE IT SIMPLE***THEN***MAKE IT WORK ! !"
NA4L's "REDNECK" FOUR SQUARE
ARRAY for 80 METERS
I have received many questions and comments about my"primitive" 80 meter four square vertical array. Each vertical is constructed of number 12, stranded, insulated copper wire. A ground buss of number 4 copper wire, with 4***8 foot ground rods, circles each vertical and the 164, 1/4 wave radials (FOR EACH VERTICAL) are connected to this ground buss. Total number of 8 foot ground rods in the array** 17 **This includes the one I have in the middle of the array at the hybrid phase system. I have a total of over 8 miles of copper wire radials under the array. Total cost of each vertical about 23 dollars!! ( I buy my wire at flea markets ). Each vertical is suspended from a large oak tree. The array is located in a dense growth of oak trees together with other plants and briars.
UP DATE**I re-tuned my "primitive" 80 meter 4 square vertical array on 11-9-08**With 110 watts into the array and the antenna TUNE frequency at 3.715 kHz, the connected array results are as follows**The array resonates at 3.791 kHz which, as you can see, is up the band about 76 kHz**The dumped power is less than 1/2 watt in all directions**The feed point impedance are between 39 ohms and 41 ohms on all antennas**After the re-tune process the F/B came up a few DB**THE SECRET**To achieve the BEST F/B on a four square vertical array***ALL the verticals MUST be on the same resonant frequency****Two of my verticals were off frequency***this was due to tree growth over the last 10 years**the NE vertical was a Little short and the NW vertical was a Little long**The TREES have an affect on the resonant frequency inMY system and all the verticalsARE NOTthe same physical length ! ! !
UPDATE on my "primitive" 80 meter four square***and***my 40 meter elevated four square array**. I was asked by John (G4ATA) to post some pictures of the arrays on his** " 4 square website "**these pictures are located at www.4-square.co.uk/na/na4l
NA4L's "REDNECK" FOUR SQUARE
ARRAY for 40 METERS
I recently re-constructed my 40 meter four square vertical array using four full-size 40 meter ground plane antennas, constructed from #12 copper wire, antenna base, elevated 29 feet above the ground. I re-tuned the array to a lower frequency (because the short-wave stations left) and I am now using coax RF choke baluns at the feed points instead of ferrite beads***The beads can cause several problems***power loss, phase shift, ( THE BIGGIE on a phased array ) permanently saturated by close lightening strikes***etc. The coax RF choke baluns eliminate RF currents from flowing on the outside of the coax cable.This assures the ground plane is doing the radiating and not the feed line. This HELPS to prevent array pattern distortion and increases the F/B ratio. The coax RF choke baluns are constructed of RG-6 coax, 13 turns, in a 4 inch diameter***single layer***DON'T"bunch the turns"as this will eliminate the choking effect. However, after several antenna tests, the ground mounted system seems to out perform the ground planes by about 8 dB to 15 dB as far as F/B is concerned. However, the gain of both arrays seems to be about the same, approximately 6 to 8 dB over my reference antennas. I am using a Comtek phasing system built by Jim Miller, K4SQR, for both four square arrays.
INTERACTION OF GROUND PLANE ELEVATED RADIALS ON A FOUR SQUARE ARRAY
AFTER RUNNING SEVERAL FIELD STRENGTH TESTS THIS SUMMER ON MY ELEVATED FOUR SQUARE ARRAY, I HAVE CONCLUDED, USING 4 RADIALS ON A GROUND PLANE ANTENNA, IN AN ARRAY,WILL DISTORT THE PATTERN AND UPSET THE SYMMETRY OF THE FOUR SQUARE SYSTEM. THE PROBLEM ARISES WHEN THERE ARE PARALLEL RADIALS. I HAVE NOW REMOVED THE PARALLEL RADIALS AND USING ONLY 2 RADIALS FOR EACH GROUND PLANE ANTENNA. AFTER DOING THIS, THE "DUMPED POWER" DROPPED AND THE F/B INCREASED SEVERAL DB. IN FACT, AFTER I DROPPED THE EXTRA RADIALS THE SYSTEM WAS LIKE A NEW ANTENNA.
EXTRA**EXTRA**GIVE A LISTEN TO THE 40 METER BAND**BETWEEN 7.125 AND 7.200**THE BROADCASTERS ARE GONE AND THIS PART OF THE BAND IS THE NEW 20 METER BAND, Hi Hi ***LOTS OF DX.I AM RETUNING AND UPDATING **MY FORTY METER**4 SQUARE**! ! ! (4-4-09)
MY NEWEST EXPERIMENT ! !
NA4L'S LAZY " H " ANTENNA ARRAY FOR 40 METERS
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 " antenna array needed two identical antennas (See the diagram at the bottom of this page). One array is broadside North and South, and one array is broadside East and West. These arrays are fed AT THE SAME TIME using EQUAL lengths of 450 ohm ladder line***Again, all the feed lines MUST be of equal length and the proper in-phase condition to each element MUST be maintained***The main feed line to my shack for this array is also 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 gain. The array is cut to operate at 7.251, 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. However, the array can be used ONLY on the 40 meter band, using this feed method. As an added plus, this array is VERY quite. After experimenting with EZNEC, the height of the lowest dipole seems to affect 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."
As of today 04-30-11, I am still in the testing mode of operation. This should be another GOOD antenna for Net Control Stations, because they can receive and transmit nearly 360 degrees at the same time ***WITH ANTENNA GAIN*** ( YOU WILL NOT HAVE TO TURN YOUR BEAM, Hi Hi ). To answer some questions***YES***This array is supported on only ONE, 100 foot tower, the ends are supported by very tall oak trees and pine trees ++++++ I am kicking around the idea of putting some one wavelength wire reflectors on the ground, under the lowest dipole antenna,,,,,there is NO good ground here in the mountains +++++ NEWS FLASH +++++ I now have some one wavelength wire reflectors under the low dipoles, these reflectors are insulated wire laying on top of the ground +++++ My next experiment will be some TUNED reflectors about one foot off the ground +++++( 05-27-11 )***More info to follow ! ! !
I am a Net Control Station for SouthCars and with this antenna pattern ( A BIG FAT CIRCLE )and several angles of radiation, this will make a great NCS antenna, along with the NVIS full wavelength loop antenna system, the "DIAMOND"SouthCars Receiving Loop and the full size four square vertical array for 40 meters ! ! !
N V I S ANTENNA
( A FULL WAVELENGTH HORIZONTAL LOOP ANTENNA, "A SKYWIRE" ,WITH A PARASITIC REFLECTOR FOR THE SOUTHCARS FREQUENCY)
NOTE 10-29-11: I HAVE FOUND THIS ANTENNA SYSTEMTO BEA SUPER SYSTEM FOR DAYTIME COVERAGE ON 40 METERS ! !
As an NVIS experiment, I constructed a 40 meter full wavelength loop antenna with a parasitic reflector cut for the SouthCars frequency, using number 12 insulated copper wire. Both square loops are horizontal to the ground. The driven loop has a total wire length of 133 feet and 1 inch, 33 feet and 3 inches on a side, and 27 feet off the ground. This loop is fed at one of the corners with a coaxial matching transformer made from 21 feet and 10 inches of 75 ohm coax ( RG-59 with .66 velocity factor ). The reflector loop has a total wire length of 140 feet, 35 feet on a side, and 10 feet off the ground. As you can see this makes the spacing .125 wave length or 17 feet apart, which is a spacing for PEAK antenna gain for a two element loop system. ( This array is beaming straight up with about5 to6 dB of antenna gain, Take a moment and THINK about this***about one S unit of gain! ! ) This antenna system is supported by trees at the corners and is under the canopy of the trees. However, at this frequency the " tree canopy " does NOT seem to affect the performance of the antenna system. This antenna will be tested for short distance communication.(50 to 400 miles) This antenna has an Omni-directional pattern and being a closed loop antenna circuit, it is very quiet. The tests so far have been very positive. NOTE :With this feed system, this antenna is a ONE band antenna***More info later ! ! !
SOUTHCARS "RECEIVING" LOOP !!
Just for kicks, I decided to construct a 40 meter, diamond shaped, full wavelength loop for receiving and noise cancelation for the SouthCars Net frequency.The diamond shaped loop is mounted in the vertical position and only 5 feet off the ground. It is fed at this bottom corner with a coaxial transformer ( 21 feet and 10 inches of RG 59 coax with .66 velocity factor ). I mounted this loop broadside N.E. and S.W. because I have a noise problem from the S.E. and MOST of all, the SouthCars stations I hear are either North or South of my location. All full wavelength loops have a very deep null off the side, so mounting the loop this way INCREASED the receiving ability and DECREASED the total noise level.
An antenna setup of this kind would be great for HAMS who have a noise problem coming from one location.
I DECIDED TO GIVE "THE GENTLEMAN'S BAND" A SHOT ! !
I CONSTRUCTED A 160 METER 1/2 WAVELENGTH DIPOLE**THE ANTENNA IS IN THE INVERTED DIPOLE CONFIGURATION AND THE APEX ANGLE IS ABOUT 150 DEGREES***THE APEX HEIGHT IS ABOUT 107 FEET AND THE ENDS ARE ABOUT 70 FEET OFF THE GROUND**THE ANTENNA IS ABOUT 500 FEET AWAY FROM THE SHACK***SOOOO THATS ABOUT IT***WE WILL SEE IF WE CAN GET A SIGNAL OUT ON 160 METERS**HI HI !!
HEY, CHECK OUT THE PICTURE AT THE BOTTOM OF THIS PAGE ! !
THATS NA4L GIVING YOU A ** HIGH FIVE ** FROM ABT 102 FEET IN THE TOP OF THE PINE TREE**THE LOCATION OF THE APEX OF THE 160 METER INVERTED Vee ! !
I was first licensed in 1963, after "messing" with shortwave radios for several years ( Popular Electronics magazine monitoring call sign of**WPE4JAM** ) and have been building antennas since I was 11 years old. I am a member of the ARRL, Ten-10 International (member number 5916), SouthCars (member number 5384 and Net Control Station) which are a GREAT bunch of guys, The OMISS NET (member number 6764) and several other Amateur Radio organizations. I am an Electronics Technology Instructor and Track and Field Coach at the local high school and have been teaching and coaching for several years****Going to retire very,very soon**Hi**Hi !!!!
Living in "the boonies" of "The Mountains of Virginia" at about 3,000 feet above sea level, I have the capability to have several wire antennas up all the time, but they change from month to month as I experiment with different designs. I have been working 80 and 40 meter DX since 1969, with several different rigs and antennas. The station I use now consists of a Yaesu FTDX-5000,( FT-2000 as backup )Yaesu DMU-2000, Heil Pro-Set Elite headset, with the H C 6 element, Electro Voice model 664 boom mike, Commander HF-2500 amp, Palstar AT4K antenna tuner, 160 meter 1/2 wavelength dipole at 107 feet, 80 meter Double Bazooka at 65 feet, 80 meter four square vertical array, a 40 meter "SPECIAL NA4L" version of a LAZY " H " array at 90 feet, 40 meter four square vertical array, 40 meter full wavelength horizontal loop with a parasitic reflector, NVIS array at 27 feet, 40 meter receiving loop at 5 feet, 40 meter 3 element QUAGI,tri-band beam at 100 feet, 6 meter beam at 105 feet, 2 meter beam at 110 feet, a few receiving arrays and many other wire antennas ! !
FYI: I have pictures and text about all these antennas on my HAM RADIO website www.NA4L.com !
AUDIO INFORMATION*****I have received many, good,unsolicited, audio reports using the FTDX-5000. It was suggested by a gentleman that I make the settings available**I will be glad to do this in an E-mail**I am using the Heil Pro-Set Elite headset with the HC 6 element OR the Electro-Voice model 664 boom mike (a1962 vintage microphone featured with the Collins equipment of years gone by)and the EQ system in the FTDX-5000**Thats it ! !
F Y I****I found a GREAT website for audio info, agc, etc. for the FT-2000,hosted by Chris ( ZL1CDP ) at www.ft-2000.com Check it out ! !
Give me a call anytime!
73's and Best Wishes from "The Mountains of Virginia" ! !
IT's A SMALL WORLD WITH HAM RADIO ! !
I'M BUILDING A WEBSITE ATwww.na4l.com
CHECK IT OUT !