Reflections on simple antennas-a Hawaii perspective


MOTHER NATURE KEEPS US BUSY

This week has been filed with enough stories to keep any news person busy.  For those of us on Hawaii Island, what was left of Tropical Storm “Fernanda” didn’t create any disturbance other than a few windward showers and some higher than normal surf along the southeast shore.  My heart goes out to those facing the trial of Hurricane “Irene”–this looks like a very nasty storm.  It’s good to see many people are preparing ahead of time for the storm’s arrival or leaving the danger area before high winds begin.  I expect amateur radio operators are gearing up for  whatever Nature throws at them.  Having experienced several hurricanes and tsnuamis in Hawaii, I know these developments should not be ignored.  It always amazes me that there are those who choose to ride out the storm rather than “get out of dodge”.  I suppose it’s a personal decision, but why tempt fate?   For us in Hawaii County, the passing of “Fernanda” gave us a good chance to assess our emergency preparedness under real conditions.  Like many Hawaii hams, I did a quick inventory of my supplies, made sure all rigs were operational, charged all batteries, and had a few easy to erect antennas ready for the event.  Most of the available antenna books have a section on building emergency verticals, dipoles, and loops.  You might want to build a few easily storable antennas just in case the need arises.

BUILDING THE ULTIMATE ANTENNA FARM…ONE CAN DREAM

While I was reading through the 24 August 2011 edition of eham.net, I came across an interesting antenna website by Tom, W8JI.  This amateur has a genuine, contest antenna farm in Georgia that makes my mouth water.  Apparently, Tom enjoys the challenge of 160-meters and takes steps to realize his goal of being a “top band” big gun.  His 160-meter four-square vertical array is impressive, as are the separate towers supporting a variety of beams, loops, and inverted “vees”.  I doubt that I could ever erect such an aluminum forest, but one can dream and perhaps glean a few tidbits of wisdom from this contester.  As I read through his website, I came to the conclusion that my modest inverted “vee” and low-lying loop were useable but not very efficienct.  He backed up his observations with a wealth of EZNEC data and Smith Charts.  I too believe in the “higher the better” philosophy, but, considering the amount of land available for my experiments and the proximity of neighbors and high voltage power lines, such dreams must be postponed until I secure a place far removed from the present qth. 

LIMITATIONS–SO WHAT DO YOU DO?

Rather than be discouraged by the unattainable, I choose to do the best with what I have–limitations nothwithstanding.  One thing I took away from W8JI’s website was the importance of cutting feed line losses and establishing a decent radial field for any verticals I choose to erect.  The last time I put up a homebrew 40-meter vertical, I laid out a haphzard radial field consisting of 16 radials of various lengths ranging from 20 to 33 feet.  My yard has definite limitations, so the wire was strung all over the place.  The antenna did a reasonable job and I did get quite a few contacts.  I found the use of 450-ohm feed line, a decent 4:1 balun, and a short length of RG-8 to the old Drake MN-4 seemed to work alright.  The Swan 100-MX remained cool and the SWR stayed below 1.7 to 1.  Nothing to write home about, but the arrangement did work.  My current all-bander (40 to 10 meters) is an inverted “vee” using two 33-foot elements attached to the tip of a 32-foot jackite fiberglass mast.  The 450-ohm feed line runs into a 4:1 balun with some RG-8 connecting the system to the Drake MN-4.  Like my old vertical, the “vee” does a good job considering the limitations imposed by my backyard.  None of my homebrew antenna projects will bust a DX pileup like Tom’s Georgia antenna farm, but it  they do allow me hours of endless fun at a reasonble cost.

WHAT’S THE POINT OF ALL THIS?

While I’m impressed by the super stations I see, it all comes down to what you can do within the boundaries of your budget and the constraints imposed by your qth.  Do the best you can with what you have.  The idea is to get on the air and not run your household into the poor house.  If you can afford the build a contest station, do so.  Yes, I want to erect a rhombic and have a set of monobanders at 100 feet.  However, with the economy being what it is, there are more pressing demands, such as paying the rent/mortgage, keeping ahead of the bills, and feeding the family.  Despite all of the challenges of the present day, you can still do a lot to enjoy amateur radio, if you are willing to build some of your own equipment, improve and maintain the rig you currently use, and experiment with antennas designed and built by you.  The key is to study, experiment, build, and use what you have made.  I enjoy the challenge.  There is a certain thrill in seeing where your signal goes once it enters the “ether”.  You can experience that sensation whether you are behind an antique like my venerable Swan 100-MX or before the newest Elecraft K3.

So, don’t give up.  Get on the air, become the best operator you can, and build your own antennas.  Half the fun is getting there and meeting someone new from the comfort of your home or club station.

Don’t forget the Hawaii QSO party this weekend.  Hawaii Island amateurs in the Hilo area will be operating from Coconut Island (Moku Ola) under the callsign AL0HA.  Have an excellent weekend.  Aloha es 73 de from KH6JRM.

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Surviving a tropical storm in Hawaii


Hawaii Island amateur radio operators are breathing more easily now that the Central Pacific Hurricane Center has downgraded Tropical Storm “Fernanda” to a tropical depression with maximum sustained winds of 35 mph.  Remnants of this once potent storm should pass south of Hawaii Island Sunday or Monday, bringing a few showers and higher than normal surf.  It appears those of us on Hawaii Island have dodged the proverbial “bullet”.  Local civil defense officials are keeping an eye on “Fernanda” just in case it pulls a switcher-roo like Hurricane “Iniki” did twenty years ago.  “Iniki” passed south of Hawaii Island as a weak tropical storm and then found warm water, regained category 4 strength, and flattened most tall objects on the Island of Kauai.  The “Garden Island” lost nearly all of its communications infrastructure, many homes, and several businesses.  It took months to rebuild the place, thanks to National Guard personnel, the work of local residents, and even amateur radio operators who lent equipment and expertise to get police and fire repeaters back on the air.  None of us who call Hawaii our home wish to see that type of storm again.

So, you can understand why many of us get a bit concerned when the National Weather Service puts out a hurricane or tropical storm message.  Hawaii residents are familiar with the drill–have emergency supplies at all times, keep the gas tank full, and be prepared to survive on your own for a few days.

Staff at the radio station where I work reherse this type of scenario frequently, so we make sure our generators are fueled, equipment and backup supplies are ready, and island communications are working.  Of course, not everything works according to plan when the “button” is pushed, but, for most emergencies, we seem to have enough depth to keep our transmitters on the air.  During the 11 March 2011 tsunami alert, most cell phone communications became marginal as use of cell sites increased.  Text messaging remained active throughout the emergency, as well as our backup analog telephone land lines.  The news room also has access to a satellite telephone, so we could communicate that way if we had too.  So, while the current activity surrounding the passage of “Fernanda” wasn’t exactly an emergency, the storm provided station staff will an excellent training opportunity.  As with any storm, one must not become complacent–that attitude could produce deadly results when you least expect it.

In my time away from the station, I checked the qth to make certain emegency supplies were handy, that my van was fueled, and that backup emergency power was available should the storm cause power interruptions.  Most of my household electronics, includiing my modest station, relies on solar charged, deep cycle marine batteries for power.  I have several easily deployed portable antennas that can be used in an emergency.  So far, I haven’t had to rely on these reserve antennas.  The under-the-house 40-meter loop provides the local and state coverage I need and seems impervious to the ravages of rain and wind.  In a pinch, I can also erect a low-level dipole to provide local HF coverage.  My only weak link is the lack of 2-meter coverage.  Several mountain ridges block Hilo from the Laupahoehoe qth, thus cutting a direct line-of-sight path to the nearest repeater at Pepeekeo.  I do get decent 2-meter signals from the Island of Maui with my 5/8 whip mounted on my van’s roof or on the metal garage roof.  The proximity of several utility poles and power lines prevents me from erected a higher 2-meter antenna.  In Hilo town, there is no problem  accessing the state-wide repeater systems and several local repeaters.

So, Hawaii amateur radio operators escaped this time.  Who knows what nature holds for us in the future.  Remember the old saying: “Things could be worse; we could be organized.”

Have a good weekend!  Aloha es 73 de KH6JRM

Simple antennas for the Hawaii Amateur, part 8


Homebrew antennas are an endless source of experiment, creativity, and occasional frustration.  Armed with a few good antenna books from the ARRL,CQ Publications, and the RSGB, I’ve built a variety of  verticals, dipoles, and loops which work most of the time.  Since I’m not an electronics wizard, there have been a few ideas that just didn’t pan out, including a homebrew 1/2 end-fed hertz that developed a bad case of corona discharge at the end of the antenna.  That 40-meter project was a disaster, but it taught a few valuable lessons about matching devices, baluns, and swr.  I think the next time I want to use an end-fed hertz, I’ll violate my long-standing rule of “rolling my own” in favor of a commercial product by Par Electronics, Radiowavz, or Comet.  I’m alright when it comes to simple verticals, dipoles, and loops.  Anything beyond that calls for more study and careful attention to detail.  I’m still in the learning process–something that will continue for awhile.  The longer I live on this blue orb, the more I’m convinced that I know less and less about more and more.  I’m an analogue freak in a digital world.  Thankfully, my news assignment in a fully digitalized and modern broadcast station (AM and FM) gives me the opportunity to stay current and hopefully out of trouble.  The mere fact that I have all the coordination of a loose bicycle chain gives me pause when I attempt to embark on another antenna project.

If you don’t prefer my cut and trim approach to antenna desing, you may want to try a few of the commercially marketed end fed verticals offered by Par, Radiowavz, and Comet.  I was intrigued  by some reviews on the eham.net site concerning the Comet CHA 250B, a broadband vertical covering 80-10 meters.  Like all compromise antennas, there are limitations that must be considered.  But, from what I gather from the reviews this antenna may be ideal for those with severe space limitations and restrictive CC&Rs.  The antenna seems to do well if it is mounted 36 to 40 feet off the ground. There was one amateur that used a DX Engineering swivel mount to keep the antenna hidden and protected when it was not in use.  This arrangement could get you on the air when all else fails.  Other than the price ($469). the CHA 250B seems to be a useful alternative to not operating at all.  In the past, I’ve use an old Hustler mast, mobile mount, and 40-meter loading coil/whip to get on the air.  Clip on a few 33-foot radials and you’re in business.  Some of my fellow amateurs have also adapted the Tarheel mobile antenna for home use.  Whatever works.  Use your creativity and get on the air.  Your mileage may differ.  I’ve loads of fun with the simple verticals, loops, and dipoles I call my antenna “farm”.   One never knows what will happen when rf leaves your skyhook and heads to the F layer…Southern Sudan, San Marino, or even Hawaii perhaps?

Have a good weekend.  Aloha es 73 de KH6JRM

Simple Antennas for the Hawaii Amateur Radio operator, part 7


This week has proven busy for those who call a broadcast news studio “their home away from home.”  With all of the debt-ceiling talk and arguments on just how insolvent we are, there is sufficient news to keep this announcer occupied.  There hasn’t been much time to relax before the ole Swan 100-MX and enjoy a casual qso.  This weekend will be fully engaged as well with a full schedule of drag races at the Hilo Drag Strip.  I work as the tower announcer, a role that keeps me out of trouble for the entire weekend.  Despite a jammed week, I’ve managed to pursue a number of antenna articles and related projects.  The August issue of “QST” contains an interesting description of an elevated 40-meter monopole with two-tuned counterpoise wires.  The skyhook seems to work alright, so, if you have a convenient tree or pole in the backyard, you may want to experiment with this antenna.  Of course, those of us without such supports will have to be more creative.  For now, my hastily built 40-meter inverted “vee” fed by 450-ohm balanced line seems to fulfill my casual operating needs.

I received a nice note from G. Brandon Hoyt on 28 July regarding his possible purchase of a Swan 100-MX transceiver.  I’ve had my Swan 100-MX since 1981.  It has served me well in both a mobile and at-home environment.  As a general purpose rig for casual qsos, the 30 + year-old solid state rig does a good job.  The rig is a straightforward, simple rig that has few “bells and whistles” and no WARC band capability.  Mr. Hoyt asked what I do about maintenance, considering the age of the rig.  I open up the rig every three months, gently blow out whatever dust has accumulated, clean all pots and switches with contact cleaner, and carefully clean all the contacts on the printed circuit boards.  These boards can be pulled out and re-seated without much difficulty.  A few caveats–before you buy the old swan, be sure it works.  I know that sounds weird, but I’ve been burned a few times on used equipment.  Inspect the power cord, check out the power supply (if it comes with the rig), and look inside for obvious signs of trouble.  Be sure to get a user’s manual for the rig.  You can get one by sending an e-mail to WA5BDR@gbis.com.  You can order a manual from Jim’s snail mail address–Jim Singleton Publications, PMB 975, Livingston, TX, 77399.  It may be a good idea to join Swan Radio Communications at this e-mail address–www.angelfirecom/ny2/hamradio.  Yahoo also has several groups that promote, preserve, and restore older Swan equipment.  Good luck.

Have a good weekend.  Aloha es 73 de KH6JRM

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