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Showing posts with the label Hawaii

Simple Ham Radio Antennas: A Portable 2 meter/70 cm Ham Radio Antenna. Post #303

KF7ETX has built an easily assembled portable VHF/UHF antenna system that can be set up most anywhere, from your home to an emergency station in the country. All it requires a painter's pole support mast , three paracord guy ropes , a dual-band 2 meter /70 meter antenna, and some low-loss coaxial cable. I have a similar arrangement at my QTH, where I use a homebrewed 5/8 wavelength 2 meter antenna supported by a 33-ft/10.06 MFJ telescoping fiberglass mast. The mast is secured by clamps on the side of my garage. I feed the antenna with 50-ft/15.24 meters of RG-213 coaxial cable. The mast can also be broken down for portable use. The antenna works very well from my rural location. The antenna used in this video by KF7ETX can be made from locally available materials from the nearest hardware or home improvement outlet. This is a simple, effective antenna that will give you hours of fun at your favorite park, beach, or mountain top. Have fun. Aloha es 73 de KH6JRM.

The Pine Tree HF Stealth Vertical Antenna. Post #289.

Now that Tropical Storm Iselle has left the state of Hawaii , those of us on Hawaii Island can complete the massive task of clearing roads, restoring power, and, in some cases, rebuilding our homes. Damage to my home was minimal with only fallen trees and "disassembled" wire antennas to be cleared from the property.  Our subdivision in the Orchidland Estates area of the Puna District escaped serious damage with only power interruption and blocked roads presenting major difficulties. When I surveyed the damage after the passing of the storm (07-08 August 2014), it soon became apparent that most of my "antenna farm" would have to be rebuilt.  The only antennas left intact were the 40/15 meter inverted vee and the NVIS 40 meter loop, which were lowered before the storm.  My 135-foot/41.15 meters doublet lodged in a 45-foot/13.71 meters tall eucalyptus tree was torn to shreds by windblown branches and fallen debris.  I did salvage the 450-ohm ladder line , a few

Simple Ham Radio Antennas. Improvised Field Day Antennas. Post #283.

The 2014 ARRL Field Day is just about history as more than 35,000 amateur radio operators transmitting from 2,500 emergency sites finish the last action-packed hours in this annual communications exercise designed to test communications capabilities during man-made or natural disasters. I always enjoy Field Day activity, whether I spend a few hours operating, logging contacts, or even taking down the rapidly assembled antennas used for this part training exercise and part contest. Over the past few years, I've used some impressive rigs ( Elecraft K3) and neatly fashioned antennas, both commercial and homemade.   This year was no exception.  As usual, I put in a few hours working for my former radio station at a "Moku O Hawaii " outrigger canoe regatta on Hilo Bay before I slipped briefly over to the Field Day site of the Big Island Amateur Radio Club at the Wailoa Visitor Center in Hilo.  I'm on a retainer to work various remote broadcasts and a few sportin

Simple Ham Radio Antennas. An 80-10 Meter Field Day Inverted Vee Antenna. Post #282

ARRL Field Day is right around the proverbial corner--28 June to 29 June 2014, to be exact.  According to the ARRL, more than 35,000 amateur radio operators used 2,500 emergency-powered stations to get on the air in 2013.   A similar number is expected this year. While many of our fellow amateurs will be heading to a Field Day site, there are a few of us, including yours truly, who will be operating under emergency conditions at home as 1E stations or as mobile stations as 1C.  For those of us home bound or forced by HOAs or CC & Rs to "hit the road" during Field Day, this national emergency communications exercise can be just as much fun and instructive as showing up a your club site. Before I retired from the commercial broadcast business, I usually worked Saturdays and Sundays in the news room, doing play by play over the radio, or hosting remote broadcasts from shopping malls and craft fairs.  Great work and lots of crazy people, but I often missed a chance to

Hawaii County Mayor declares Amateur Radio Week in Hawaii County. Post #281.S

Source:   Hawaii Tribune-Herald , 14 June 2014. Reporter:  Bob Schneider (AH6J), ARRL Pacific Section Manager. In tribute to Hawaii Island hams who provide emergency communications for Hawaii County during times of natural or man-made disasters, Hawaii County Mayor Billy Kenoi has declared 23-29 June 2014 as "Amateur Radio Week" in Hawaii County.  Mayor Kenoi has urged the public to support the American Radio Relay League 's (ARRL) Field Day events set for Saturday, 28 June 2014, when amateur radio club members will set up and demonstrate emergency communications equipment and skills. In Hilo , the public is invited to activities hosted by the Big Island Amateur Radio Club (BIARC) from 8 a.m. to 5 p.m. at Walmart.  A Field Day station will be operational from 8 a.m. Saturday until 8 a.m. Sunday at the Wailoa Visitor Center in Hilo.  During that 24-hour period, local ham operators will contact other amateur radio operators across the Pacific and North America.

Simple Ham Radio Antennas. A basic 40/15 meter dipole. Post #276

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My antenna "farm" at the new QTH finally is taking shape. So far, I've built and used successfully a 40-10 meter inverted V fed with ladder line , a 5/8 wavelength vertical for 20, 15, and 10 meters, a 135-ft/41.15 meters "classic doublet" fed with ladder line that works from 80-10 meters, and a 40-10 meter delta loop fed with ladder line.  I've described these antennas in past posts.  All of them work very well with relatively low power (less than 50 watts) with my older rigs (Argosy II, Swan 100 MX, Yaesu FT-7, and a Kenwood TS-520). Although I prefer multiband HF antennas fed with 450-ohm ladder line, I still use a few single or two-band antennas fed with 50-ohm coaxial cable when I wish to experiment on 40 or 15 meters.  Last Sunday, 18 May 2014, I decided to build a simple two-band dipole covering the 40 and 15 meter bands using a single piece of RG -8X coaxial cable. The dipole would be designed for the lowest frequency range and then use the thir

Simple Ham Radio Antennas: The Ghost of Antennas Past--the simple vertical. Post #269

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Over the past few posts, I've been describing some of the antennas I designed, built, and used during my days as a novice amateur radio operator (1977-1978).  Most of the working designs were copied into school theme books and saved for future reference. One of my favorite homebrewed antennas was a simple vertical  antenna supported by a high tree limb terminating with a slightly angled ground plane consisting of 10 radials.  The antenna was designed for 40 meters and worked very well for contacts throughout the Pacific Rim and the mainland United States . Last weekend, I decided to duplicate that antenna with some spare wire, ceramic insulators, coaxial cable , and basic tools. As mentioned earlier, the process of moving to a new home often uncovers items you once thought were lost.  Such was the case here when I found several 50-ft /15.24 meters rolls of #14 AWG house wire in the garage.  That wire would serve as the vertical element and the rudimentary ground radial sys

Simple Ham Radio Antennas: Sam's "James Bond" Antenna. Post #264

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Whenever I get a day off from my substitute teaching duties, I try to attend meetings of the Hawaii QRP Club at the Hilo, Hawaii Jack In The Box Restaurant.  The meetings usually last from 0600 to 0900 local time and cover a variety of topics, from antennas to homebrewed equipment.  Attendance varies from to 2 to 7 or 8 persons, depending on who's working or free for the day.  Dean Manley (KH6B) usually brings some of his antenna notebooks and his vast storehouse of experience as a radio broadcast engineer to the meetings.  There's always something interesting or new at these gatherings. Recently, some of us have been discussing homebrewed antennas that can be operated from areas restricted by HOAs, CC&Rs , or just plain lack of space.  One of the most intriguing antenna ideas came from the late Sam Kumukahi (KH6AFS), who, during the 1990s, used what he called a "James Bond" antenna with excellent results for local and occasional DX contacts.  At the 27 Febr

Simple Ham Radio Antennas: The 10 meter 1/2 wavelength sloper. Post #262

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The sloping 1/2 wavelength dipole is one of my favorite antennas.  "Slopers" are good antennas for restricted space areas.  They are simple to build, inexpensive, and exhibit some directivity in the your chosen direction. According to VK6YSF, VE2DPE, and other amateur radio operators, a properly designed 1/2 wavelength sloper radiates energy at low angles relative to the horizon with vertical polarization.  Slopers don't require a ground radial system and can be fed with a good grade of 50 ohm coaxial cable.  A sloper antenna only requires one tall support (tree, mast, edge of a roof, etc.) and occupies less space that a 1/2 wavelength horizontal dipole. So, let's build one of these simple, effective antennas for the 10 meter band , centering on 28.4 MHz --right in the middle of the techncian class phone band. MATERIALS: One tall support.  In my case, I used a 33-ft/10.06 meter MFJ telescoping fiberglass mast.. One 5-ft/1.52 meter wooden stake to support

Simple Ham Radio Antennas: The W3EDP antenna revisited. Post #261

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The "classic" W3EDP antenna has been around since March 1936 when Yardley Beers (W3AWH/W0JF) described a multiband antenna built by his friend H.G. Siegel (W3EDP).  Siegel used the traditional method of "cut and try" to arrive at an antenna length that would work satisfactorily on 160, 80, 40, 20, and 10 meters. Beers remembered that "A length of 84 feet (25.60 meters) seemed to stand out as being the best of all the combinations tried."  A similar "test and tune" method was used to determine a satisfactory counterpoise length of 17 feet (5.18 meters), "as the one working best in combination with the antenna." Since that time, several variations of this true "Zepp" antenna have been developed to facilitate portable, emergency, and even home use.  Many QRP enthusiasts use some kind of W3EDP-derived antenna for their operations.  The W3EDP antenna is a simple, cheap, and field deployable.  The antenna requires a 1:1 or 4:1

Simple Ham Radio Antennas: A Low HF Band Triangle. Post #259

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Over the past few years, I've built a variety of HF antennas for my amateur radio station.  All of my verticals, inverted vees, dipoles, and loops have been a learning experience, especially when I've been faced with limited resources and space.  Operating from an apartment or a home governed by CC&Rs and HOAs has been a challenge. Now that I'm slowly moving into a full acre of space in the rural Puna District of Hawaii Island, my space restrictions are gone and there are no committees to oversee my antenna activities.  I count this as a definite blessing.  For the first time in many years, I can build full sized dipoles, verticals with a decent ground system, and large full-wave loop antennas without interference.  Since my new property is surrounded by tall trees approaching 50 feet/15.24 meters, my antennas are well shielded from prying eyes.  When I operate out of my rental home in Laupahoehoe, I'm still hemmed in by utility poles and neighbors.  My antenna

Simple Ham Radio Antennas: Antennas without tuners, part 4. Post #257

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So far, the "tunerless" antennas I've built have worked very well.  They have been made with locally available materials from my "junk" box, neighborhood garage sales, and the nearby Ace Hardware Store.  These antennas have consisted of individual dipoles/inverted vees for my bands of preference (40, 20, 15, 10 meters), telescoping fiberglass masts (33-ft/10.06 meters tall), a single RG -8X coaxial feed line , and supporting wooden stakes or tree branches. Dipoles for each band were built on the ground and were later hoisted into position via a halyard and pulley system.  A "choke balun" made from part of the RG-8X feed line was attached to the mast just below the center connector at the top of the mast. In my first multiband antenna system, I changed bands by lowering and raising the appropriate antenna into place.  I couldn't change bands by staying in the shack. My second system was a modified "fan dipole/inverted vee" using mul

Simple Ham Radio Antennas: Antennas without "tuners", part 3. Post #256

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In some of my previous posts, I've investigated, built, and used multiband dipole and inverted vees using a single 50 ohm coaxial feed line .  With a telescoping fiberglass mast (33-ft/10.06 meters extended), a simple halyard and pulley system, and separate antennas cut for each band of use (40, 20, 15, and 10 meters), I've been able to change bands fairly quickly by lowering the dipole/inverted vee elements, substituting those of another band, and raising the new antenna.  With each band element cut for the desired frequency, the efficiency is high with low swr for that band.  Since each antenna element is trimmed for the lowest swr at my mast location, an antenna transmatch isn't necessary.  Sometimes, as in the case with the 40 meter dipole/inverted vee, an antenna cut for the cw portion of the 7 MHz band will often work well on the phone portion of 15 meters (21 MHz band). The 15 meter band will operate on the third harmonic of the 40 meter band . In order to save