Posts

Showing posts from April, 2012

Simple Antennas for the Radio Amateur--a continuing series

How would you like to build a cheap, easily erected, and efficient antenna for your small yard?  I've pondered that idea over the past several days after a cold front and its associated high winds made a mess of my temporary, homebrew vertical next to my garage.  Since I had a few days off from my substitute teaching assignments, I decided to build another sky hook with materials I had in my "junk box."  I still had a good pvc mast, about 100 feet of number 14 housewire, and an extra 4:1 balun stashed in the corner near the washing machine.  Along with 50 feet of 450 ohm twin lead and about 20 feet of RG-6 coax, I was in business.

The antenna would be an inverted "vee" inspired by a variety of articles in the ARRL Antenna Book, various amateur radio forums (e.ham, net), and a 1998 paper entitled "The $4 Special" by Joe Tyburczy, W1FGH.  The antenna won't rival a mono band beam on a 50-foot tower, but it will provide hours of good contacts at a smal…

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

Do you remember your first amateur radio antenna?  I certainly do.  It was ugly, fed by cheap RG-58 coax, and connected to my first rig, the Heathkit HW-101.  I called it a dipole only because each side of the Budwig connector had 33-feet of 20-gauge wire attached.  The ends of this homebrew skyhook were attached to two trees about 35-feet high in the back yard of the teachers' cottage near the Honokaa High School.  That was 36 years ago--a time long gone except for my memory of many contacts as a novice and techncian class operator.  I surely had fun with this crude antenna.  It was home made and it was my own.

Now jump forward to 2012.  I've been a general, advanced, and extra class ham since those glory days 3 1/2 decades ago.  I've gone through many rigs (most of them second-hand and well-used) and several types of antennas.  Yet, I still haven't lost the excitement of those novice class days.  For me, designing and erecting antennas are still fun, educational, and …

Mentoring ("elmering") Young Hams

Today, I had a break from my normal substitute teaching duties at Laupahoehoe High and Elementary School.  Now that I had a free day, I could spend a few hours catching up on email and various amateur-related posts.

I came across an interesting  article in today's edition of eham.net, which encapsulated much of what I feel is right with amateur radio.  Don Keith, N4KC, wrote a nicely-paced short story called "A Dark and Stormy Night".  The plot revolves around a back porch discussion between a newly licensed 15-year old ham and two older hams, who happen to be husband and wife.  The trio was reviewing what it meant to be an amateur radio operator while a thunderstorm and a power outage played out on a warm summer night.  All of the usual reasons for being an amateur radio operator and the service hams bring to their communities are given in an easy to understand, conversational tone.  Keith has the unusual ability to make you feel part of the story.

What impressed me most …

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

Those of us forced to use compromise antennas brought on by limited real estate, restrictive CCRs, and HOA (home owner associations) may have another way to enjoy amateur radio without worrying about the neighbors.  The May 2012 edition of "QST" has several interesting articles about HF digital operations.  I was most interested in an article by Steve Ford, WB8IMY, called "Who's on JT65?"  Despite its limitations, this mode for moonbounce communication developed by Dr. Joe Taylor, K1JT, is becoming more popular as the year rolls on.  Ford says, "the key to JT65's burgeoning popularity is found in the fact that you can use it to make contacts over great distances with a few watts and just about any antenna.  As you can imagine, hams confined to indoor operating have embraced JT65 with a passion."  Ford goes on to describe the experiences of Ron Kolarik, K0IDT, and Sergey Kohno, UR3CTB, in Ukraine as models of what this mode can do.  There are limit…

Simple antennas for the Hawaii Island Amateur Radio Operator--a continuing series

Have you ever thought of installing a small, portable HF rig and collapsable antenna in your vehicle for impromptu or emergency operations?  During the past week, wet weather and sometimes marginal road conditions got me thinking about what HF radio system I would use should a traffic emergency arise where I couldn't get home or where cell phone coverage would be unusable.  Along the Hamakua Coast of Hawaii Island, cell phone coverage is spotty and there are many areas inadequately served by this handy communications device.  Geography plays a big role in limiting cell phone coverage, with mountain peaks and ridges often degrade the signal available.

So, last week I decided to make a small upgrade in my mobile capability with the creation of a small, easily portable HF system to complement my bare-bones 2-meter capability (HT with mag-mount antenna on the rood of my van).  I selected my old, trustworthy Yaesu FT-7 (10 watts output), a large marine, deep cycle battery in the garage,…

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

One of the joys in making your own antennas is to discover what others have done in similar circumstances.  A visit to the antenna forums on QRZ.com and eham.net can give you a lot of useful information, particularly if you must operate from a deed-restricted area or from a small backyard as I do.  I am amazed at some of the clever antenna designs that my fellow amateur radio operators have used to get around HOAs, CC&Rs, and lack of space.

Another good source of ideas for those of us in space-restricted areas are books and articles dealing with small antennas, stealth antennas, and concealed opertions of various sorts.  Although most of us can get by with the antenna books published by the RSGB, ARRL, and CQ Communications, there are a few sources I would recommend from personal experience.

The first book on my list would be "The Short Vertical Antenna and Ground Radial" by Jerry Sevick (SK), W2FMI.  This small volume offers several useful and effective designs for the …

Simple antennas for the Hawaii Island Amateur Radio Operator--a continuing series

While I was searching through some boxed electronic parts in the garage this afternoon, I discovered an old Hustler mobile mast, bumper mount, shock spring, and coils for 40 meters, 20 meters, and 15 meters.  When I first became an amateur radio operator back in 1977, I used the Hustler system on my then almost new 1976 Toyota Corolla.  That was a very small vehicle and I had to be creative in placing an old Swan 260 Cygnet transceiver in front of the passenger's seat.  Fortunately, the Toyota had a metal bumper which was able to hold the mobile mount and antenna.  After I bonded all the body and engine bolts with copper braid and installed special spark plugs, the system became a cumbersome, but successful mobile installation.  When I moved to my present location in Laupahoehoe and bought a new car, I cleaned and stored the old mobile antenna in the garage and gave the old Swan transceiver to a new ham who didn't have a rig.  Since that time, I haven't done much in the wa…

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

Thanks to a Good Friday holiday and some decent weather, I've been able to re-erect my "antenna farm" in the backyard of my small lot.  Both the 40-meter vertical (with its tuned counterpoise) and the 20-meter vertical dipole went up without problems thanks to the fiberglass poles I used for masts.  The antenna was was replaced because of storm damage.  Fortunately, I had some wire left over from a studio rebuild at my former radio station.  So, I didn't have to make a 30-mile trip to Hilo for wire and connectors.  The under the house 40-meter loop survived the storms and didn't require any repairs.

Once I got my skyhooks in the air on Thursday afternoon, I decided to try 15 meters, since that band is usually busy around 2100 hrs UTC in my location.  As luck would have it, conditions were only fair with considerable QSB and other annoyances.  However, I heard a CQ from Dick, W8PW, in Las Cruces, New Mexico and decided to hit the transmit switch on the old Swan 100…

KH6JRM's Amateur Radio Blog-simple antennas continued

Now that some clear weather has returned to Hawaii Island, I've been able to fix most of my antennas that were damaged by high winds and the 25 inches of rain my qth received during a very wet March.  Most of the repairs went well.  The fiberglass poles were a little scratched by airborne debris and the wire elements were a bit twisted around the masts, but, in general the antennas came through the storms alright.  I was able to lower the masts most of the time before I left for school and that prevented more damage from the high winds.

I erected my two verticals in their original configurations--one a 40-meter inverted vee with the apex at 33 feet and the other a 20-meter vertical dipole stretched out on an old 33-foot MFJ fiberglass pole.  Both antennas were fed by 35-feet of 450-ohm balanced ladder line into a MFJ W9INN 4:1 balun.  A short run of RG-6 coax (15 feet) was connected to my trusty Drake MN-4 ATU.  That in turn was connected to the old Swan 100-MX at the operating des…