Simple Antennas for the Hawaii Amateur Radio Operator, part 6

Here are a few more unusual and somewhat offbeat antennas I’ve used with varying degrees of success.  All of these “creations” work to the extent that you will get some contacts.  I’ve lived in a few challenging places where amateur radio antennas were never part of the landlord’s world view.  Although my current qth is quite nice, it is still restricted to a small lot shared by 3 other modest rental homes and is approximately 20′ away from utility poles.  With all of the salt air and moisture found on Hawaii Island, you can imagine the corona discharge problems I face several times a year.  To be fair, the Hawaii Electric Light Company does its best to keep the transmissions lines inspected and cleaned.  On an island with about 4,000 square miles, line maintenance is a major headache for the telephone, cable, and power companies.

In my antenna book for 2002, I found a stop-gap antenna that served me well while the backyard was being torn up for a new septic tank and water lines.  In place of a normal radial field for the trusty 40-meter vertical, I attached one line of the 450-ohm twin lead to the antenna and the other to my qth’s metal roof.  The roof was bonded together.  After I scraped off a bare spot and attached the other lead, I fired up the old Swan 100-MX (20 watts or so).  With the help of my trusty Drake MN-4 ATU, I was able to get a decent match on all bands between 40 and 10 meters.  Nothing spectacular, but the substitute ground plane seemed to work.  I was able to make my infrequent appearance on the daily 40-meter interisland net with reports ranging from 56 to 58 on ssb.  Once the backyard work was done, I restored a normal ground system and painted over the roof area used for the antenna connection.  I’m not sure how efficient this antenna system was, but it did allow me to get on the air.

Recently, I’ve tried out a system used by many recreational vehicle owners.  I had an old mag mount with a 20-meter “Ham Stick” in the garage.  While the Odyssey van was parked on the lawn for a car wash I never did complete, I placed the mag-mounted “Ham Stick” on the van’s roof, attached four, 16.5 ‘ radials to the antenna mount, and ran some RG-8 into the qth, and began a fun afternoon.  This primitive system worked well and I made several decent (57) ssb contacts to the U.S. mainland.  SWR was fairly low across the band (1.7 to 1).  With the ATU in line, I was able to improve the swr a bit.  Again, nothing fancy, but the lashup did work.  Once I figure out how to mount a permanent antenna on the van, I can use that system as a backup to the rig in the house.

The weekend lies ahead and that means some operating time.  Aloha es 73 de KH6JRM.

Simple Antennas for the Hawaii Amateur Radio Operator, part 5

One of the things I’ve enjoyed most about being an amateur or ham operator in Hawaii is the fairly consistent good weather for building and erecting home-brew antennas.  Other than our rainy season (November to March, generally), antenna experiments can be done in an unhurried fashion.  Since I’m not the most mechanically inclined operator, I need all the time I can get to make something that works.  In the 37 years since I was a novice class ham, I’ve built a large number of skyhooks that were just plain awful and a few others that were gems–largely because they worked despite my “cut and trim” approach to the art of antennas.  Over the past 3 decades, a combination of study and gradually increasing technical skills have enabled me to erect a number of antennas that not only look presentable, but also do a decent job of launching rf into the “ether”.  While most of my antenna projects have been modest because of space restrictions, I’ve managed to make simple loops, verticals, and dipoles that give me hours of pleasure.

Occasionally, I run across a few antenna designs that can best be termed “unusual” or even bizarre.  When I pulled out my antenna notebook for 1997, I discovered an intriguing design by K3MT called “Grasswire Antenna:  another approach to hidden rf antennas.”  The antenna first appeared in an April 1997 internet post.  Basically, K3MT end-fed an 85′ piece of #12 gauge insulated wire through a trifilar balun wound on a T-200-2 core.  He laid the wire on the grass and attached a counterpoise wire (he also used an 8′ ground stake as an alternative to the counterpoise).  He ran some coax to his shack and voila!  He had a wire that seemed to work fairly well.  His article contained a number of graphs which seemingly demonstrated how well the antenna worked.  His attached log showed a string of 559 to 599 reports from many stations.  He also designed a “grass” off-center fed dipole for those that prefer a G5RV or dipole configuration.  Whatever the limitations of this antenna might have been, it was a winner from the stealth point of view…out of sight, out of mind for nosey neighbors and HOAs.  K3MT said he could just roll up the antenna when he was done.

With all that in mind, I made a “quick and dirty” 20-meter dipole, fed it with RG-8 coax, laid the contraption on the front lawn, and attached the “ground warmer” to the Drake MN-4 ATU.  I actually made a few 20-meter contacts on Saturday afternoon.  Nothing fantastic (539 to 559), but I did make a few qsos.  Of course, I did a lot better when I attached the dipole as an inverted “vee” to my 33′ pvc mast.  I don’t know if this sort of antenna would be useful to those of  you facing severe operating restrictions.  You may want to experiment with this idea.  Who knows?  This antenna could give you an alternative to not operating at all.

Now that the news shift is over for the day, it’s time to head home for a few hours of operating time.  Have a good day and get on the air.  Aloha es 73 KH6JRM.

Simple antennas for the Hawaii ham operator, part 4

This weekend has turned into a decent antenna day for amateur radio operators on Hawaii Island.  Since I completed most of my newsroom duties early this weekend, I was able to work on a few antenna ideas I first tried in my early days as a novice operator.  I pulled out my antenna notebook for 1978 and found a bunch of antenna ideas under the November category–a fairly wet month according to historical records.  That may have been the reason I fashioned a few “quick and dirty” verticals capable of being erected and taken down between drenching tropical showers. 

One of my vertical helix antennas proved useful and fairly cheap to construct.  Borrowing freely from the “ARRL Antenna Book” and various publications from the RSGB (Radio Society of Great Britain), I assembled a compact portable unit that could be used in an emergency.  I decided to re-build this skyhook on Saturday.  It works well, considering its narrow bandwidth sosme high angle radiation. 

I found an unused 10-foot piece of schedule 40 pvc pipe under the qth and decided to press this plumbing project left over into antenna service.  I spiral wound 66-feet of #22 gauge hook-up wire on the pvc pipe, attached a 9-inch diameter aluminum pie plate to the top for some top loading,  hooked up eight, 10-foot radials with detachable clips, and fed this contraption with some 450-ohm twin.  The twin lead went to my DX Engineering 4:1 balun and then to the trusty Drake MN-4 ATU.  A small piece of RG-58 coax mated the system to the venerable Swan 100-MX.  Does it work?  Yes, it does, with a very narrow bandwidth.  The helix can also work  the amateur bands from 40 to 10 meters, given that tuning will be very critical.  According to the “ARRL Antenna Book”, a spiral wound helix of approximately 1/2 wavelength for the band of your choice should give you a compromise 1/4 wavelength vertical.  The impedance measured at the base of my homebrewed vertical helix was around 5 ohms, so there are quite a bit of losses.  The losses dropped once I added several more radials.  There is a difference of opinion on the length of the radials–some say the radials should be at least a 1/4 wavelenth for your design frequency,  Others I have read claim the radials should be as long as the length of the antenna support–in my case, around 10-feet.  Since my backyard is small, I will use as many radials as I can.  The helix does work and it could help you get a signal launched if there is no other choice.

I’ve modified the original support, dividing the 10-foot pvc pipe into two, 5-foot pieces, which can be joined to set up the antenna.  The antenna, 10 radials, a small antenna tuner, and a deep cycle battery now reside in the back of my Honday Odyssey van, ready for use.  In the future, I will set up this emergency antenna at a public park and see what I can do….so far, the old Yaesu FT-7 (at 10 watts) has garnered a few contacts using this system at the home station.  I do better with the Swan 100 MX, but for portable use, I’ll stick to the old Yaesu.

Next on the design table is the building of a vertical dipole designed around the helix idea, with each section using 66-feet of #22 gauge wire, fed by 450-ohm twin lead.  Antennas along these lines can be found in most antenna books.  I tried this arrangement a few years ago, with some success on 40-meters.  Of course, results will depend on  your location, propagation, and available materials.  My “junk box” had a good source of materials, so I didn’t have to spend much for wire and pvc pipe.

Another approach for those of us challenged by CC&Rs, noisy neighbors, and lack of space would be to build a simple dipole using “ham stick” mobile antennas for your band of choice.  I’ve used this type of antenna in the past.  This antenna will get you contacts, although not as many as a dipole up 40 to 50-feet.  Be creative with what you have–the idea is to experiment and to get on the air despite the limitations of your surroundings.  Our amateur radio experience is a continuous learning process.  For me, the stress relief and brief escape from our severely misaligned world are worth the effort.  There’s something intriguing about launching rf into the “ether” and seeing where it goes.

Have a good weekend…..Aloha es 73 de KH6JRM.

Simple antennas for the Hawaii Amateur Radio operator, part 3

The inverted 40-meter “vee” described in my previous post is performing well considering the severe space restrictions at my qth.  I would prefer some nearby trees to support a 40-meter dipole at a decent height (around 40 to 50 feet), but those living antenna supports are a few hundred yards away, so I will work with what I have. 

As I examined some of my earlier antenna notebooks, I discovered a few antenna designs that may prove useful in your situation.  When I first became a novice in 1977, I used a random length wire approximately 50′ long tacked to the ceiling of the teacher’s cottage my xyl and I called home.  I stretched out the wire as straight as I could and ran the antenna in and out of two bedrooms and the living room, which served as the operator’s position.  The wire was attached to a homebrew tuner and a 50′ counterpoise was attached to the tuner’s ground screw.  The counterpoise wire snaked along the house’s baseboard.  A low-pass filter was placed before the tuner to reduce any TVI that may be generated by my old HW-101 transceiver.  I hoped that running low power (around 20 watts or so) would eliminate any “rf” bite on the microphone and reduce the impact on any nearby electronics.  I was lucky.  I received no complaints and my television reception was unaffected.  I managed to get quite a few contacts with this less-than-optimum arrangement.  If you find an indoor antenna to your liking, you may want to look up an interesting an article by Zack Fruhling, KD6DXA, called “How to make an indoor random wire antenna.”

As you can imagine, I didn’t get many 599 reports (except for statewide contacts).  At the time, a 559 to 579 report was enough to keep my amateur radio interest alive.  I soon discoved the obvious–an outdoor antenna is better than one enclosed room, and an indoor antenna is better than no antenna at all. By November 1977, I retired the old inside-the-house random wire for a small, top loaded vertical helix in the backyard of the teachers’ quarters.  I ran 16 radials of varying lengths around the lawn and under the cottage.  This antenna was a lot better than my indoor skyhook, but the bandwidth was quite narrow.  Now I was getting a few 599 reports from the west coast of the U.S. mainland.  As you suspect, I have a preference for cw.  I’m on the radio station microphone 12-hours a day, so I look forward to giving the voice a rest.  Anyway, I later connected a length of 300-ohm television twin lead to the vertical helix and found I could work 40-meters through 10-meters.  Nothing outstanding to be sure.  But I now had an antenna that allowed me to enjoy serveral bands.  Later on, I purchased a few antenna books from the ARRL and the RSGB and started a program of self education on antennas.  Now, there are many antenna modeling  materials that make homebrewing antennas a real treat and a real time saver.

The whole point of this retrospective review of my many antenna blunders and occasional flashes of understanding is to realize that ham opertors learn by doing.  Armed with good theory, basic tools, and a williness to learn, you can accomplish much of what you once thought impossible.  When I first was licensed by in 1977, there were no other hams in my neighborhood, so I read a lot and joined the Big Island Amateur Radio Club, where I found several seasoned hams who were willing to help this rank novice.  Since those early days, I have tried to help as many new operators as I can…afterall, we were all beginners at one time.  Thanks to by background in commercial broadcasting, much of the theory supporting amateur radio  was already known and practiced.  That gave me an edge when it came to advancing up the amateur radio licensing ladder.  By the time I finally, reached Amateur Extra in 2005, I had enough experience to be dangerous.  I spent 15 years as an Advanced Class because of work requirements and a stubborn bit of laziness.  But, that’s another tale for another time.  Procrastination can be a real impediment to progress.

In sum, don’t ever give up, be it in the amateur radio realm or in your daily life.  Work for a goal whatever your station in life.  As for antennas, build your own if you can.  I get satisfaction from designing and building my own equipment, be it an antenna or a small, low-powered transceiver.  For me, such projects help relieve the stress of a newsroom job and allow me to reconnect with the rest of the world.  Don’t be afraid to build a simple vertical or dipole…you may be surprised at the results from both a technical and financial point of view.

Aloha from Hawaii-the Big Island.  KH6JRM.

Simple Antennas for the Hawaii Ham, part 2

‘Just a few more thoughts on simple antennas before I shut down the newsroom for the day and head to the qth.  In the previous post, I described an unsophisticated, basic antenna that could get you on the air quickly with a minimum of effort.  You can erect a simple 40-meter dipole with coax feedline in a variety of configurations, ranging from a straight dipole and inverted “vee” to a sloper and a vertical dipole (if you have a tall mast).  This basic antenna will work well on 40-meters and give acceptable service on 15-meters (using the 3rd harmonic of the 40-meter band).  I’m using one these simple inverted “vees” in my backyard and it does well for casual rag chews and interisland service.  My pvc mast is 33′ high at the apex and the 33′ dipoles go off at an angle, meeting two 5’ stakes at either end.  I get reasonable interisland coverage as well as decent DX to the west coast of the U.S. mainland.  I believe there is a degree of  high angle radiation as well, giving me some good local coverage.  My primary NVIS antenna is the 40-meter loop strung under the house, which is elevated approximately 6-feet off the ground on a post and pier system. 

This bare-bones antenna can be pressed into multi-band service if one replaces the coax feed with 40-50 feet of twin lead (either 300 or 450 ohm).  Attach the twin lead to a 4:1 balun (DX Engineering makes several well-built baluns for a variety of applications), run a short length of coax (RG-8, 9913, RG-8X, or even RG-6 with suitable connectors) to your antenna matching device (tuner), and then connect the tuner to your rig.  You may have to experiment with the length of twin lead to keep swr low–I’ve found any length approaching a  half-wave length for your lowest band will often present loading problems and eratic readings.  The ARRL Antenna Book explains this situation and provides twin lead lengths that will make your tuner happy.  I replaced the RG-8 coax last night in my inverted “vee” and substituted some 450-ohm twin lead for the coax.  I can tune anywhere between 40 and 10 meters with ease.  I suppose there is some radiation from the twin lead, but that doesn’t seem to bother the rig or the electronics in my home.  As with my other verticals, I can swivel the pvc mast to ground level, which presents a low profile to the neighbors and reduces the possibility of a lightning strike entering my antenna system.  Swivel systems can be found in the DX Engineering catalog.  This antenna is easy to erect and requiress no radial system.  I’ve had a difficult time creating a decent radial system, owing to the small size of my backyard.  In a pinch, I’ve used an elevated counterpoise system with my vertical antennas.  This arrangement works and presents a comfortable load for the tuner, but its performance is lackluster. 

None of these antennas will outperform a beam or a dipole 50′ above ground, but they do work.  Considering my space limitations, I’m satisfied with my homebrew inverted 40-meter inverted “vee”– a simple antenna that gets me on the air and provides hours of enjoyment at a minimal cost. 

Paging through my old antenna and log books, I’m surprised at just how effective these simple antennas are.  Of course, propagation plays a huge role.  Nonetheless, I’ve worked the world with verticals, inverted “vees”, and loops.  You can do it as well.  For those of us on restricted budgets, a vertical made from locally obtainable resources could keep “you in the game.”

May your log be filled with DX.  Aloha es 73 de KH6JRM.

Amateur Radio on Hawaii-the Big Island

Over the past few days, I’ve been reviewing some of my old antenna notes.  Like the late Lew McCoy, I keep most of my ideas in an antenna notebook for future reference.  Any notebook will do, as long as you keep yourself organized and have sufficient room for drawings, meter readings, and other perameters.  Although there are many good, inexpensive antenna design programs, I prefer the old style of jotting down thoughts in a notebook.  I’m not a technophobe, but after immersing myself in the latest digital, whizz-bang equipment and programs at the radio station, I just feel the need to retreat to a simpler time as far as amateur radio is concerned.  Anyway, I’ve accumulated 20 or more student composition notebooks full of radio ideas, failed experiments, and occasional successes.  Some of my early antenna designs were quite pathetic, but that’s how one learns.

While I was going through a notebook dated October 1976, I came across a very simple 40-meter antenna that has served me well over the years.  Nothing can beat a 1/2 dipole fed with RG-8, RG-58 (if that’s all you have), and even RG-6.  Get that dipole up as high as you can, trim for lowest swr, and feed the skyhook with 50 watts or so.  Depending on the time of day, band of choice, and propagation, you should be able to work many stations.  If you prefer 40-meters, just measure out 65′ of whatever wire you have (I prefer #14 gauge, but use what you have available),  cut two segments of 32′, 6″ each, attach and weather proof your coax connection.  The antenna will do a satisfactory job on 40-meters and will probably be useable on 15-meters.  You may have to attach some “outrigger” wires with clips to make the antenna more workable on 15-meters.  This is about as basic as it gets for a functional antenna.  If you have space problems like I do (very small backyard), you can make an inverted “vee” dipole by using a 30-35′ pvc mast.  The dipole will perform a bit better than the “vee”, but the vee only needs one support.  I’m using the vee now, and I find it satisfactory for my needs.

In future posts, I will review some of the antennas that have proven successful in my restricted circumstances.  Meanwhile, it’s back to work.  Have a great day and get on the air.  Aloha es 73 de KH6JRM.

Amateur Radio on Hawaii Island

What a busy weekend!  Thanks to some excellent weather, Hawaii Island residents were able to select a range of community events to spend with their families. Our radio station covered a bunch of events, ranging from the Hawaii Island outrigger canoe paddling championships to the July Points meet at the Hilo Drag Strip.  The weather has improved considerably since late June, when most of us on “the rock” thought the seasons had been reversed.  Usually, our rainy season runs from November to April with generally clear, warm weather balancing out the remainder of the year.  However, this year, rainy conditions extended into June.  The rain was welcome, since most of the island has been griped in an extended drought that began almost two years ago.  There has been rain, but not enough to keep pastures green and crops growing.  Even Hilo, which normally gets around 120-130 inches of rain per year, has received only about 40 inches so far, about 20 incles below normal.  Since many rural residents rely on catchment systems or private wells, any shortage that leaves tanks below half-full is call for concern.   Those of us living on former sugar plantation lands with built in  water systems (reservoirs, installed pipes, and distribution systems) fare a little better.  Of course, our weather problems are minor compared to the heat wave that is baking the nation’s mid-west and south-west.  I guess we islanders should count our blessings.  There’s nothing quite like a partly sunny day with 10-15 mph trade winds and a temperature hovering around 75-80 degrees.

The favorable weather gave me a few hours to repair antennas in the back yard.  The effects of salt air, wind, and sunlight are noticeable after a few weeks on any antenna structure on Hawaii Island, be it our station’s towers or my own modest 40-meter vertical.  Maintenace and repair are constants in this paradise graced by storms and volcanic eruptions.  Volcanic haze (vog) is especially corrosive on metal surfaces.  The Kilauea Volcano has been active since 1983.  The output of this formation has dumped millions of tons of sulphur dioxide into the atmosphere.  Once the gases combine with moisture, one sees the formation of sulphuric acid and other compounds which can damage crops, buildings, car metal, and even antennas.  The weekly wash and wax routince for the van is one of those tasks that must be done.

So far, I’ve been able to keep ahead of the corrosion attacking the “antenna farm”.  Thanks to coax-seal, enclosed plastic containers, and other weather-proofing techniques antenna maintenance isn’t a big chore.  As for the various rigs that launch my mighty 10 watts into the either, I always keep them covered after operating–this step keeps most of the dust and air-borne pollutants away from swithches, dials, and relays.    Hawaii hams residing near the shore experience more corrosion problems than those of us above the 1,200 level.  The corrosion problem is especially acute for our local power utility (Hawaii Electric Light Company).  Company crews have line maintenance and replacement schedules in effect that keep most problems to a minimum.  Of course, unexpected events such as auto accidents, lightning, and termite damage can down a pole at any time.  So, brownouts and power losses are always players in keeping the QTH supplied with electricity.  Rather than depend on commercial power for my amateur radio activities, I’ve opted for deep cycle marine batteries charged by solar panels.  I also have a standby generator in case I need to power something in the house or run higher power.

Amateur Radio in the rural areas of Hawaii presents a challenge, but one that usually ends positively if alternate power sources are incorporated into the station arrangement.
I keep my system simple–easy to build antennas, reliable rigs, and modest power demands.  Your mileage may vary–one should do as much with their amateur radio interests as finances allow.  For me, resources are limited, so I resort to what I have available for my various projects.  You’d be surprised what the local hardware or automotive supply store can offer for the radio amateur.  If one is creative and watches the expenses,  amateur radio can be enjoyed without breaking the family budget.

Have a good week and get on the air–no matter how humble your station is.  The object is to have some relaxing fun amidst the turmoil of this uncertain decade.  Of course, you may have a lot more fun with a 100-foot tower, a four-element mono beam for 20-meters, and an Alpha amplifier.  One can dream.  Now, if I could only get a federal “stimulus” package to fund my amateur radio fantasies,  I would have nothing to complain about.  Alas, reality for me is a Kenwood 520 (plus other old rigs), an ancient J-38 key, and an ultra simple and cheap 40-meter vertical.    Aloha es 73 de KH6JRM.

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