Simple Antennas for Amateur Radio Operators–a continuing series


KH6JRM’s Amateur Radio Blog, post 160

NEW USES FOR OLD COAXIAL CABLE

ANTI-THEFT PROTECTION FOR EQUIPMENT

One of the things I enjoy when I’m not behind the key or microphone at my amateur radio station is reading historical material pertaining to amateur radio.  This sub-branch of the amateur radio hobby has given me several ideas on antenna improvement, reusing old materials in new ways, and protecting valuable equipment with a minimum of effort.

What do you do with old coaxial cable?  I tend to follow the advice of E.A. “Whit” Whitney, W1LLD, who wrote a brief article about reusing lossy cable in the 11th Edition of “Hints and Kinks for the Radio Amateur” (published by the ARRL in 1982).  Whit’s article is found on page 5-13 of this excellent compendium of practical ideas from past issues of “QST”, the official journal of the American Radio Relay League. 

In Whit’s own words, coaxial cable “that’s become too lossy for use as  transmission line” can be used “for radials in your ground system.  Lengths of the sheathing can be removed from the cable and installed as ground or bonding straps around your equipment, in your boat or on your car.  A length of such cable makes a good shielded lead from your car battery to your mobile radio.”  In the past, I’ve used old lengths of RG-6 obtained as scrap from cable installation companies for radial and counterpoise systems.  In most cases, these old cables work well in this new application.  In my case, I got old cable for free or for just a few dollars.

Another problem amateur radio operators face is the loss of equipment through theft and the identification of such equipment when police recover the stolen radio and station accessories.  As in the previous discussion on coaxial cable, the 11th Edition of “Hints and Kinks for the Radio Amateur” contains a few suggestions on how you can handle the issue of anti-theft protection.  On page 7-4, Paul Zender, AA6PZ, has a few ideas to make the recovery of your lost equipment a bit easier.  Paul writes, “amateurs wishing to protect their equipment from theft shold mark it with the abbreviation of their state and driver’s license number.  This makes it easier to trace through police computers than using social security numbers or an amateur radio call.”  Check with your local police department to see if it participates in “Operation Identification”.  You may be able to borrow engraving tools for marking household valuables, including your radios.  Stickers can be attached to indicate that the property is marked and the identification recorded with local law enforcement authorities.

I’ve marked my equipment and I hope you will do the same.  Have a good, safe weekend.

Aloha es 73 de KH6JRM–BK29jx15

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Simple Antennas for the Amateur Radio Operator–a continuing series


PURPOSE OF THIS SITE

Over the past few days, some of my readers have asked why I put this site together and to whom  the information is directed.  These are fair questions, since my interest in Amateur Radio (Ham Radio) may be far from your concerns.

I have two reasons for writing this blog:

1.  The blog serves as a personal journal about my journey through interpersonal communications and my love for all things electronic.  I’ve been a licensed amateur radio operator for 35 years.  I’ve enjoyed every moment of the experience, from building equipment to designing my own antennas (the things that launch signals into the atmosphere).  I was fortunate to have had a good electronics background courtesy of the United States Air Force and over 40 years in the commercial broadcast business.  Very early in my radio journey, I helped design and build the student FM radio station at the University of Hawaii (Manoa), worked at various radio stations, and even put a part 15 (unlicensed, low power) AM station on the air from my house.  Before I became a school teacher, I retired as the news director of Pacific Radio Group stations on Hawaii Island.  So, you could say electrons run in my blood and may have scrambled my brain.  Everyday, I look forward to contacting friends around the world.  Sometimes, I even get to practice my Russian with hams in Moscow and in other parts of the Russian Federation.

2.  The blog also serves as a record of my experiences in overcoming obstacles presented to the pursuit of my radio hobby.  One of the things amateur radio operators do the most is design and build antennas.  Sometimes an efficient antenna creates friction with neighbors, who consider towers and supported wires a detriment to their sense of aesthetics.  In fact, restrictions placed on amateur radio operators by CC&Rs (covenents and restrictions), HOAs (Home Owners Associations), and the sheer lack of physical space have led many amateurs to seek other ways of continuing their hobby.  Presently, the U.S. Congress has mandated the FCC (Federal Communications Commission)  investigate how housing laws restrict the emergency operations of amateur radio operators.  One of the requirements of an amateur license in the United States is to provide emergency backup communications should regular channels go down.  Amateur radio operators have provided communications support to local agencies during times of emergency, such as hurricanes, fires, tsunamis, earthquakes, and other natural disasters.  Many hams feel that the growing restrictions against outside antennas will restrict their ability to respond in times of emergency.  Congress and the FCC will eventually figure out  some sort of solution to this problem.

Meanwhile, many amateur radio operators, including yours truly, are trying to make the best of a contentious situation.  That’s where I come in.  After three and a half decades on the air, I have accumulated a lot of experience in designing and building simple, cheap, and inobstrusive antennas that will serve those operating in restricted situations.  The antennas I use in my crowded neighborhood are nearly invisible from the street and can be lowered to ground level during periods of inactivity.  Eversince I adopted this low impact antenna philosophy, there have been no complaints about unsightly structures or ruined views of the countryside.  So, I share what I’ve learned with other hams in the hope they, too, will find something useful in their situation.

Amateur radio operators are the descendants of Marconi, Popov, Hertz, De Forrest and others who have pushed back the frontiers of knowledge.  To paraphrase Sir Isaac Newton, “I stand on the shoulders of giants.”

Have a good and safe weekend.

Aloha es 73 de KH6JRM–BK29jx15


SOMETHING DIFFERENT FOR THE ANTENNA EXPERIMENTER

The weather has improved to a point that I can get outside and play with antennas again.  Other than a twice-daily walk and jog with my xyl, the weather has kept both of us inside.  June on Hawaii Island often brings many days of showers, and this past week was no exception.  So, when the sun finally broke out for several hours, I rushed through my daily chores and proceeded to the postage stamp lot in back of our rental house for some serious antenna work.

Because the inverted vee, loop, and “upper and outer” antenna were doing well, I decided to make a vertical helix for 40 meters using some short pvc pipe, extra #22 AWG wire in the shack, and some 450-ohm balanced line into a balun and the trusty Drake MN-4 ATU.

According to information I found in several ARRL publications, a quarter wave vertical could be created by winding a half wavelength of wire around a sturdy pole and topping the end with a capacitance hat.  I’ve seen amateurs use vertical helix antennas designed for 80 meters with some good results.  Of course, a good radial field is necessary to make these shortened antennas perform.

Anyway, I wound 66 feet of #22 AWG wire along a 10-foot piece of schedule 40 pvc I had under the qth.  According to theory, that arrangement should give me an antenna roughly equivalent to a 33-foot vertical.  I attached an 18-inch capacity hat to top of the wire helix, connected one lead of 450-ohm wire to the helix, connected the other lead to a 33-foot counterpoise, and joined the entire system to a 4:1 balun and the Drake MN-4.  The homebrew vertical helix had a very narrow tuning range, but it did work on 40 and 15 meters with the help of the Drake MN-4.  I tried the helix on 20 and 10 meters with some degree of success, but the antenna seemed to work best on 40 and 15 meters.  The Drake MN-4 remained cool on all bands and I did not get any rf “bite” in the shack.  I was running 15 to 20 watts cw with no problem.  I tried a few SSB contacts at 50 watts and was pleased to get some good reports.  The vertical helix probably has more losses than my trusty inverted vee, but it does work and it does let you be heard.  Of course, results could be better if I had enough room to establish a decent radial system.

The vertical helix is easy to build, easy to disguise, and very portable.  The antenna is nearly invisible from the street in front of the qth, owning to its small size and proximity to local trees.  As is the case with my other antennas, the vertical helix can be swiveled down to ground level when I am not using it or when storm clouds approach.

I may use another helix on a longer pvc pole to get on 75 and 80 meters–frequencies which are difficult to operate from my location. 

I will let you know how that project turns out.  Meanwhile, have a good day and get on the air with something you have designed and built yourself.

Aloha es 73 de KH6JRM–BK29jx15


A VHF ANTENNA FOR YOUR APARTMENT

Apartment dwellers face unusual antenna problems, whether they be the  installation of HF antennas or VHF antennas.  Like many of you, I’ve resorted to using my handheld attached to a mag mount atop a refrigerator or other piece of interior metal.  While this arrangement works, it can be unsightly or even dangerous.

It seems Yvon Laplante, VE2AOW, has come up with an apartment antenna which is not only effective and cheap, but also disguiseable and safe.  Laplante’s idea can be found in the “Hints & Kinks” column of “QST” for July 2012.  In Laplante’s words, “I made a small dipole antenna using telescoping antennas I took from old, broken FM radios.  The antenna is mounted on a…3 x 5 inch piece of Plexiglas with two suction cups.  With my radio placed close to a window, I attached the antenna to the window and adjusted the two elements for 2 meters–about 19 inches.  The antenna gives very good results.”  This antenna has low visibility and can be easily moved to better locations in the apartment. 

This afternoon I tried a similar antenna in the bedroom facing the island of Maui (a repeater there is about 75 miles from my qth.  The repeater is on the slopes of Mt. Haleakela).  Getting 2 meter signals to a local Hilo repeater is quite difficult with several ridges and mountain slopes directly in the path from my qth to Pepeekeo (just outside of Hilo–about 22 miles from my house).  So, most of us along the Hamakua Coast rely on the Maui Island repeaters for coverage.  Anyway, I taped two 18 inch pieces of #22 AWG wire to the bedroom window and fed them with  RG-6 coax via a HI-Que coax connector.  My old Kenwood handheld (TH-21) was able to raise two Maui repeaters with this arrangement.  My usual 2 meter antenna is a Larson 5/8 wave mag mount on the metal roof of my garage.  The Larson provides a better signal, but the “lash-up” I copied from VE2AOW seems to work fairly well.  I’ll keep this homebrew antenna as an emergency backup to the Larson on the garage roof.

I have a similar set up in my van.  I placed an 18 inch vertical element and an 18 inch horizontal element fed by RG-6 coax on a window attached to the right sliding door.  I provided some slack so opening the door won’t damage the coax.  While this antenna is a compromise, it does serve me well in Hilo town, where I can hit several local repeaters with my Kenwood TH-21 handheld.  I keep this old Kenwood as a spare and as a mobile rig for the van.  Even at the low power setting, I  can get solid copy in and around Hilo.

Aloha es 73 de KH6JRM–BK29jx15

Simple Antennas for Amateur Radio Operators–a continuing series


A NEW ANTENNA FOR APARTMENT DWELLERS

The July 2012 issue of “QST” contains an interesting antenna article by Jeffery Brone, WB2JNA.  The article entitled “A Dipole Doesn’t Have to be Straight–There’s always a way to put some kind of antenna into service” runs from page 36 to page 37.  Brone’s idea may give you another way to get on the air despite severe space restrictions.

Simply put, Brone ran approximately 35 feet of light gauge wire (#22 or #24 AWG) to  a balcony of his third floor apartment and ran another 35 feet around the apartment, “tacked up along the ceiling and corners, resulting in a full size dipole for 40 meters.”  He fed the antenna through a MFJ manual tuner with  3 feet of homemade laddder line (2 inch spacing between the wires)  “and it loads up on all bands–40 through 10 meters.”  Running low power (15 watts cw), Brone has been able to work Chagos Island, Africa, and South America.

Brone says common sense applies when you use this homebrew antenna–avoid folding the wire back on itself and use low power to minimize RFI and exposure to RF.  Brone concludes his excellent article with what he calls the “10 rules of stealth/apartment/restricted antennas”:
“Something for an antenna is better than nothing.”
“More wire is usually better than less, unless the antenna is only meant for one band.”
“Balanced (center fed dipole or vertical) is better than unbalanced (end fed wire), all other things being equal.”
“All other things are seldom equal.  Try different arrangements.  Read up on the subject.”
“Get a tuner.  A low priced manual one is okay.  You’ll want it for some bands and will appreciate the flexibility it gives you.”
“Get a dummy load, too.”
“Keep the power low for safety and less RFI.”
“CW and digital modes produce more contacts than SSB.”
“Listen, listen, listen.”
“Put up the best antenna you can manage, then get on the air and have fun!”

Indoor antennas do work if you allow for their limitations.  When I first became a Novice operator back in 1977, my first antenna was a 70-foot loop tacked to the ceiling of the teacher’s cottage my wife and I shared in Honokaa.  Fed with 300-ohm twin lead and hooked to a balun and a Drake MN-4, the homebrew loop did a good job on 40 and 15 meters.  I still have the old Drake MN-4, so I guess the tuner survived my initial efforts at antenna design.

Now, I have an inverted vee, an “upper and outer” vertical with counterpoise, and an under-the-house 40 meter loop.  My small backyard can just accommodate the vertical and the vee.  I suppose I’m luckier than many who face CC&Rs, HOAs, and no backyard space.  Give this bent dipole of WB2JNA’s a try–it could open an entire new frontier for you.

Aloha es 73 de KH6JRM–BK29jx15

Simple Antennas for the Amateur Radio Operator–a continuing series


FIELD DAY IN HILO, HAWAII

The Big Island Amateur Radio Club endured rain, heat, and wind to complete another successful ARRL Field Day at Hilo’s Wailoa Visitors Center.

Frequent rain showers and unsafe track conditions led to the cancellation of the June Points Meet at the Hilo Drag Strip.  The closing of the track freed a few hours to enjoy the ARRL Field Day with the Big Island Amateur Radio Club.  I was only able to spend about 3 hours with club members, but I did see some interesting antennas and displays at the visitors center.

When I arrived for the 0800 W start of the event, the sky was overcast with scattered showers–a perfect time to erect antennas!  By the time I got squared away, the club had erected a 40 meter vertical and a hardy cw operator starting logging in contacts on 15 meters.  The erection of the triband beam had to wait until the skies cleared and the threat of thunderstorms subsided.  While all of this was going on, the trusty vertical and a Yaesu-857D kept KH6EJ (club call) on the air.  The rig ran off several deep cycle marine batteries until the tribander and a 3-element yagi could be erected.  The club also had a mobile station (class 1-C) using a 20 meter hex beam.

About 35 club members and 50 or so local residents attended this edition of Field Day.  A reporter from the “Hawaii Tribune-Herald” newspaper interviewed several club members and took a long series of photographs for the paper.  By the time I left at 1130 W, a second rig was added to the mix, making the club fully operational as 2A Pacific.  A small Honda generator and a bank of solar cells were used to charge our batteries.

The weather was quite wet and gusty through Saturday night.  There was some clearing by early Sunday morning, so some of the weather was favorable for raising and lowering antennas.  Club members, friends, and family brought sufficient supplies of food and drink to keep the over night operators fully fueled.  The club also had a media display, handouts from the ARRL, and an emergency communications kit for the public to examine.  Hawaii County Mayor Billy Kenoi declared Saturday, 23 June 2012, as “Amateur Radio Field Day in Hawaii County”.  So, the club got quite a bit of print and electronic publicity.  My former employer (Pacific Radio Group) ran public service announcements about Field Day, as did some of the other radio stations in Hilo.

Considering the poor weather conditions, participation by both amateur radio operators and the general public was excellent.  The Wailoa Vistors Center was large enough to accommodate club members, county officials, and the public.  All told, club members did an excellent job of getting out the word about Amateur Radio.  Several local residents expressed an interest in upcoming license classes taught by club members.

I trust your Field Day went well.

Aloha es 73 de KH6JRM–BK29jx15

Simple Antennas for Field Day


FIELD DAY ANTENNAS

The ARRL’s traditional Field Day Emergency Communications Exercise begins shortly.  For Amateur Radio operators in the state of Hawaii, the fun begins this Saturday at 0800W and ends Sunday at 0800W…a full 24-hours of emergency operations, a near contest atmosphere, and, most of all, outrageous fun!.

This year, the Big Island Amateur Radio Club will use the grounds of the beautiful Wailoa Visitor’s Center in Hilo.  The site is open to the public and is covered in case of summer rains.  Although the club will be running 2A Pacific with solar and generator power, there is commercial AC available for the evening and morning meals.  Ah yes, the food.  As was the case last year, club members will prepare something at home and bring their surprises to the center.  I’ll be bringing a case or so of soda and fruit juce to keep the operators fueled throughout the long, sticky night.  Once I get through with the drag races at the Hilo Drag Strip (I’m the tower announcer for this event),  I’ll drive over to the operating site and settle in for a few hours of logging and operating.

Field Day brings out all kinds of operating equipment.  Last year, the club had a variety of rigs, including the latest Kenwood and Yaesu transceivers.  But what brought me out last year was the diverse selection of antennas available.  The club put up an impressive tribander, a set of phased verticals for 40 meters, and, on one occasion, strung a full wave, 80 meter loop between several palm trees.  That antenna was quite a performer.  This time, the club will have a tribander, a phased vertical array (most likely for 40 meters), and a surprise for 80 and 160 meters.  Satellite operations are also on the schedule.

Most likely, I’ll spend some time with our newly licensed amateur radio operators, giving them some experience in a contest-like situation.  As was the case last year, I’ll be doing logs while the new operators try to make contacts.  All of this is great fun.  At about 10 p.m., I’ll  bid farewell to my fellow amateurs and head home for a good night’s sleep.

For those of you who can’t get to a club site, a home-based operation, running 1E (emergency power) or 1D (commercial mains) could be quite an experience.  I ran 1E a few years back and thoroughly enjoyed the excitement.  My equipment was modest–an old Swan 100 MX and a homebrew inverted vee fed by balanced 450-ohm line.  That old antenna is still in use as is the venerable Swan.  I think I made around 150 contacts before my eyes and fingers gave up at around 3 a.m. Sunday morning.  I wasn’t worth much of anything on Sunday, but I surely had fun!

So, even if you can’t make it out to a club site, give Field Day a try.  You might even run a mobile operation for some added excitement.

I hope to hear you 23/24 June.

Aloha es 73 de KH6JRM–BK29jx15

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