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Showing posts from June, 2012

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  transmi…

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 …
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 se…
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."  T…

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 w…

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 KH…

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 …

Simple Antennas for the Amateur Radio Operator--a continuing series

AN "ALL-BAND" ANTENNA THAT REALLY WORKS

The best laid plans of man and beast often go astray.  Such was the case today, when planned antenna maintenance took a back seat to heavy showers and gusty winds rolling off the Pacific Ocean.  Along the Hamakua Coast, such occurances make travel a bit hazardous and any outdoor work a study in frustration.

So, with tools in hand, I returned to the ham shack for plan number 3.  Plan number 2 was doing some repairs and maintenance around the house.  Now that I'm semi-retired, I find there is sufficient time to keep the house orderly while pursuing a variety of amateur radio interests.  Once the housework was done, it was once again out to the shack for some general clean up and antenna research.

One of my favorite research tools is the "Antenna Wire Classics" published by ARRL.  I'm currently paging through volume two of this outstanding series.  What I was looking for was a simple, multi-band antenna that was easy to bu…

Simple Antennas for the Amateur Radio Operator--a continuing series

More emergency antennas for hams:

There is a wealth of wonderful and somewhat curious antenna ideas in the amateur radio library.  I have several books published by the ARRL which I 've found useful in my restricted space environment.

As I was paging through "More Wire Antenna Classics, Volume 2" (Copyright 1999-2006 by the ARRL), I ran across two articles on using ordinary lamp cord for both antenna feedlines and antenna elements.

"A Zip-Cord Special Antenna" on page 1-6, Chapter 1 (taken from the "QST", May 1972) describes how one ham pressed about 80-feet of ordinary lamp cord into service as both feedline and radiator for  a 75-meter  schedule he was running with some of his friends.  Apparently, this operator was on vacation and lacked some materials to maintain his contacts with  his hometown.  He found that the emergency dipole performed well in his temporary location.  He also fashioned a version for 40-meters, which he found useful on 15 meters.…

Simple Antennas for Amateur Radio Operators--a continuing series

ANOTHER SIMPLE ANTENNA

While I was reading the 13th edition of the ARRL's "Hints and Kinks for the Radio Amateur (copyright 1992),"  I came across an interesting article by J.A. Ciciarelli, WB3DDM, on strain relief for coaxial cables.  It wasn't the excellent suggestion of using garden hose or automotive heater hose to reduce strain on the coax that caught my eye,  but rather the type of antenna he chose for his operation.

Apparently, WB3DDM prefers to use long-wire antennas in the inverted -vee configuration.  According to J.A., " I feed the antennas 1/4 wavelength from one of  the leg ends so that I can use coax transmission lines (each leg is an odd multiple of a 1/4 wavelength).  Thus, the feed point is not at the apex, but along one of the sloping legs.  This arrangement frequently creates a sharp bend at the coaxial connector."  And so enters his idea of using hose to relieve some of the strain.  The process is illustrated on page 7-8 of this edition.

An…

Simple Antennas for the Amateur Radio Operator--a continuing series

WHEN DOUBT, IMPROVISE!

During a recent read of the articles posted on eham.net, I came across an interesting antenna story by Dale Kubicheck, N6JSX (12 June 2012).  The article entitled "HF 18VT Vertical Fence Mounted With an Ugly-Balun" caught my eye because of the way this ham recovered, rejuvinated, and restored an old vertical antenna to its former glory.  This article contains a series of pictures and descriptions of the creative process leading to a semi-homebrew antenna that really works.  Once Dale rewound a few coils, cleared the corrosion from the antenna sections, and fashioned a new balun, he attached the antenna to a chain link fence, which formed part of his counterpoise system.  Although he may need some radials in the future, the antenna apparently delivers the results Dale wanted.  Dale's pictures and explanation are excellent.

Eventhough you may not have the tools Dale uses, you can still make a good antenna with what you have on hand.  Even an old 108&qu…

Stealth antennas for the Amateur Radio Operator

STEALTH ANTENNAS FOR CHALLENGING SITUATIONS

In my last post, I outlined a few ideas that could get you back on the air despite restrictive covenants, HOAs, and limited space.  I've tried many of those designs myself with varying success.  Despite their shortcomings, hidden antennas can work if you're creative, run qrp, and use digital modes.  Since I enjoy SSB at times, I've had to be certain that my signals don't overload nearby stereos, tv sets, and even telephones.  Some of the newer electronics have very little filtering and are subject to overload with even moderate power levels (100 watts).  Add to this the proliferation of apartments, condominiums, and generally closer neighbors, and you get a situation where amateur operators can get blamed for everything.  I've had my share of complaints, even when I was off the air! The mere sight of an antenna can let some people's imaginations run wild.  A few years ago, I had a neighbor who complained that my Yaesu …

Simple Antennas for the Amateur Radio Operator--a continuing series

HIDDEN ANTENNAS

Are restrictive covenants, limited space, and nosey neighbors ruining your amateur radio hobby?
There is no need to retire your amateur radio activities because of antenna issues.  With a little creativity, low power (QRP), and light gauge wire, you can enjoy amateur radio again.  While this "below the radar" or stealth operating technique can't rival the performance of a mono band beam on a tall tower, it can get you back on the air.  You might even have some fun and save money at the same time.

I'm always on the lookout for interesting antenna ideas, especially since my "antenna farm" is confined to a small backyard and faces close-in neighbors and high voltage lines.  Although I've used indoor antennas with some success, I prefer getting the rf outside if at all possible.

Today, I revisited a website maintained by Julian Moss, G4ILO.  Julian's well-designed blog provides a compact, easily understood tutorial on hidden and low visibili…

Simple antennas for the Amateur Radio Operator--a continuing serie

STEALTH ANTENNAS

During the past few weeks, I've read many articles from amateur radio operators who are facing restricted options because of HOAs, CC&Rs, and limited space.  Although I'm not in a restricted zone, my small lot and proximity to power lines makes me feel some of their pain.  People move into restricted quarters for a variety of reasons, so I'm not going to rehash the obvious arguments presented in the media.  Suffice to say, we amateurs must use our creativity if we are to enjoy our hobby to the fullest.

I've made a practice of reading as much information as I can about stealth and hidden antennas to get an idea of what's possible for my hobby.  Every once in a while I come across articles which peek my interest and get the creative juices flowing.  Today, for example, I ran across WB0DGF's Antenna Site (wb0dgf.com/stealth.htm), which provides a practical antenna plan for a home and various links to antenna designs and options.  Among the ideas…

Simple Antennas for the Amateur Radio Operator--a continuing series

ANOTHER EMERGENCY ANTENNA

There are quite a few birds in my area that often use my antennas as perches or launching platforms for their flights.  Normally, the smaller birds (finches, cardinals, and an occasional native bird like a honey creeper) don't create problems.  However, a sizeable bird such as a pu'eo (Hawaiian Owl) can damage a dipole or even the bird itself.  Such was the case yesterday when some kind of bird bumped into the 450-ohm twin lead feeding my 40-meter inverted vee.  I cut out the damaged section of the feedline and decided to replace it temporarily with about 50 feet of RG-6 I had stored in the "junque" box.  I didn't have the Drake MN-4 ATU handy at the time, since the MN-4 was being cleaned on the workbench (the kitchen table).

So, I borrowed an idea from Dean, KH6B, and rigged up what he called a "James Bond" antenna--named after the famous fictional spy created by Ian Flemming.  All I did was connect the coax to one end of a UHF …