Welcome to Handiham World.

You can do it!  
Today, just as we did last week,  we are going to begin with Troubleshooting 101 as part of our initiative to help new ham radio operators (and even some of us older ones) learn how to do some basic troubleshooting for ourselves. Yes, it can be tempting to ask someone else to do things for us.  This can become a bad habit when it keeps us from learning new things, especially things that we could – with a bit of practice – learn to do for ourselves.  Knowing these basic things can serve us well in the future when no help is available.  This next simple exercise is one that we will be practicing at this summer’s Radio Camp.  You can do it yourself once you learn a few basics.

Troubleshooting 101

I have my General Class license now, so I decided to put up a vertical antenna, which I ground-mounted, in my back yard. I have checked the SWR (standing wave ratio) and it is practically one to one. It is grounded with a ground rod right near the feedpoint, and I have kept the grounding wire short. I am putting out plenty of power with my 100 watt rig, but I am having a hard time making contacts? What is wrong here?
Vertical antennas have long been the subject of derision in many amateur radio circles. It is practically an article of faith that “a vertical antenna is one that transmits equally poorly in all directions”. These operators have either tried vertical antennas themselves and had a poor experience or (more likely) they have heard some know-it-all pontificating on the awfulness of verticals and the awesomeness of just about any antenna other than a vertical.
Yes, the poor old vertical has gotten a pretty bad reputation. But is it justified?
I say no! And here’s why.
The most common vertical antenna design is an electrical quarter-wave long. This means that a simple 20 meter vertical will be on the order of 16 to 17 feet tall (5 meters). There is no problem ground-mounting a vertical in most locations, and this kind of antenna is sometimes disguised as a flagpole in places where there are restrictions on traditional antennas. A ground-mounted vertical will certainly have other advantages, too. It will not require an expensive tower or other supporting structure. It will be easy to install and work on if it needs maintenance or adjustment because you can reach it without any climbing. You can trench the coaxial feedline under the ground to keep it out of the way. If it is mounted in the back yard, it will probably not even be visible from the street. No wonder this simple antenna seems so attractive!
But let’s get back to your troubleshooting question. You have done well with your vertical antenna installation as far as it goes, but you have made a common mistake. You have assumed that a ground rod would suffice as a complete grounding system – but it won’t. When we work with RF (radio frequency) energy, we must remember that RF grounding is not the same as providing a simple electrical ground for low-frequency AC, DC, or lightning protection. Yes, a good electrical ground is an essential part of a well-designed antenna and feedline system. Now it is time to complete your vertical antenna installation with a good RF ground. That means installing radial wires extending from the base of the antenna outward in all directions. The ground rod should work as a common connection point. The coax braid is connected to the ground rod or the antenna’s mounting post, both of which are tied together with a stout, solid conductor.
What is happening in your antenna system is that lots of current is flowing in the vertical element right near the feedpoint. This is normal and expected. There is also a lot of current flowing in the ground beneath and around the antenna, outward in all directions. That is because a quarter-wave vertical is like one side of a dipole system, except that the ground makes up the other half of the dipole. If you recall your General Class studies, you will remember that current in a half wave dipole flows most strongly right near the feedpoint.
Now, answer me this: If you put up a dipole with one leg made of a fully-extended wire and the other a very short wire connected to a big resistor, do you think that dipole would work as well as a dipole with both legs made of wire?
No? Why not?
“Well”, you say, “It is obvious that the dipole with a big resistor in it will not work as well because there will be power lost in the resistor. The resistor will heat up, just like a dummy antenna.”
Yes, you are right! In fact, dummy load antennas are really nothing more than resistors designed to dissipate RF energy to keep it off the air while you run tests on a transmitter. A dummy load will have a near-perfect SWR, even though it is a resistor. Just because it has a low SWR does not mean that it is a good antenna. The problem with your vertical antenna system is that it is like that dipole with a resistor in one leg. The ground beneath the antenna has resistance to the flow of RF energy outward in all directions. The soil does have some conductivity, but it depends on moisture and composition. So the ground can be like a resistor. The ground rod you have installed goes straight down and does nothing to help RF flow in all compass directions outward near the surface of the ground.
The fix: A good radial system.
Radial wires are installed like the spokes of a wheel, outward from the grounded side of your antenna’s feedpoint. They can be cut to a quarter-wave length for every band you plan to operate (if your antenna is a multiband vertical) or – and this is more practical – to whatever length is convenient to fit into the space you have. Mind you, this goes only for a ground-mounted vertical in an area with normal to good soil conductivity. If you are mounting a vertical over quartz rock with almost no soil, the tuned radials might be necessary. If you are in the USA Midwest with its rich soil, you can probably get by with random length radials in your ground-mounted system. The reason is that conductive soil pretty much detunes the radials anyway, so there is nothing to be gained by carefully measuring them. In fact, since most of the RF current will be flowing right near the feedpoint, it makes sense to provide it with a low resistance path there, close to the antenna.
Why? Think of the formula power dissipated = current squared times resistance. The higher the resistance in the ground, the more power will be dissipated as heat. You don’t want that! What you want is for most of the power to be used to make contacts with other stations. The earthworms will be happier, too, because they don’t need the extra heat. If most of the current flows in the ground near the antenna, then THAT is where you need to put the most radial wire. I have always simplified this concept when teaching about vertical antennas by using the following practical example:
You have a coil of wire to use for radials. It is 100 feet long and will provide the radial system for your 20 meter band quarter-wave vertical. The question is which of these choices would be better:
A. One long radial that uses all 100 feet of wire.
B. Two 50 foot radials running in opposite directions.
C. Three 33 foot radials spaced 120 degrees apart.
D. Five 20 foot radials spaced at 72 degrees apart.

If you were thinking about losses near the feedpoint, you would probably pick answer D. The reason is that you are putting more wire near where the loss is actually happening! In fact, the thing with radials is “the more, the better”, not “the longer the better”. Of course you would not want to go to extremes and assume that 100 one-foot radials would work. But in the real world, you want to get more wire down in the ground near the feedpoint. A dozen radials work better than four.
Installing and testing the system:

Stomp the grass back down and you are good to go. Repeat for each radial. If you can go out 33 feet in one direction and only 15 in another, that’s okay. Just make sure that the final installation is solidly connected to the ground rod and coax braid and all of the wires are out of the way of the lawn mower. The insulated wire will last longer in the ground than non-insulated wire. Once you get a taste of a hands-and-knees radial installation, you will not be eager to repeat it to replace rotted out wire any more than you have to. And if you tried to install springy radial wire, well, you know what that is like. Push one part in, another part pops out.

Email me at [email protected] with your questions & comments.  
Patrick Tice, WA0TDA
Handiham Manager

One World Trade Center

Here in Manhattan, the highest point above the hustle and bustle, is the Empire State Building. Or, it was at least until yesterday. As of April 30th, 2012, the new One World Trade Center is officially the tallest building in Manhattan. As I listened to the news yesterday morning this got me thinking about the antennas on the Empire State Building, and the logistics and history of them. For those of you fascinated by these things, here are a collection of resources to consult, and some of what I learned about the tallest antennas in the city.

I found a great article on the history of the TV mast at www.lnl.com/esbantennas.htm.  The TV antenna portion was originally a mooring mast for dirigibles which was re-purposed 8 months after the building was completed in 1931.  The article was a reprint from Broadcast Engineering magazine, August 1967.  The mooring mast, which was part of the original design of the building, was supposed to be used by passenger airships for anchoring, while the passengers disembarked down a gangplank to the 102nd floor.  In reality, this proved to be unsafe, as the updrafts and other air currents around the building would not allow for safe mooring.  Only one dirigible ever successfully anchored to the mast after a 30 minute ordeal with mooring ropes, and even then was only able to stay anchored for 3 minutes.  The first entity to transmit from the re-purposed mast was NBC who began experimental TV transmissions from the ESB in December of 1931.  For you fans of  TV’s Fringe, the sequences shot in the alternate universe, show modern dirigibles moored to the Empire State Building, as well as a skyline that still contains the Twin Towers.

Here also, is another great article; from CQ Amateur Radio, March 2011, Digging Deeper With Bill Baker, W1BKR, where Bill visits the transmitter site for channel 13, WNET, in the Empire State Building.  Great pictures of the mast, and of the massive filter network that all signals have to pass through first to reduce interference with each other.

Today there are over 130 antennas on the Empire State Building at various heights.  This site lists the options available to anyone interested in locating an antenna up there.  I’m not sure how many Amateur Radio repeaters are on the building as of today, but one I know for sure is KQ2H.  KQ2H has a large linked network of repeaters that give it incredible range, including a 10 meter input up in the catskill mountains.  I can listen to the ESB 220, 440, and 900 repeaters from my desk at work, and get an idea of what’s going on with 10 meter propagation by taking note of where the incoming stations are.  Lately I’ve been hearing hams from Australia and New Zealand hitting the repeater late nights between 8 and 10 PM EDT.  KQ2H’s 10 meter FM machine transmits on 29.620, and listens on 29.520.  It is usually available on EchoLink, although the link has been down lately.  On EchoLink you need to search for the callsign W2FLA which belongs to the linked 2 meter repeater in the system up in the mountains.

Antenna Mast at the E.S.B. from CQ, March 2011 "Digging Deeper with Bill Baker"

Many of these entities that have antennas on the ESB, relocated there after the Twin Towers fell in the 9/11 disaster.  I was looking for antenna leasing info for the new One World Trade Center building, but nothing seems to be posted yet.  There is definitely going to be an antenna structure on the top of the building though.   I’d love to take a couple of radios up to the ESB observation deck sometime, but I hear the officials can be a little touchy about these things (understandably so).  As I learn more about One World Trade Center I’ll post it at a future date.

Does anyone else out there have stories about antennas on skyscrapers (like the former Sears Tower in Chicago, or even the CN Tower in Toronto)?  Leave some info in the comments.  73.

–Neil  W2NDG

Stormville Airport Flea Market

Yesterday was opening day at the Stormville Airport flea market, which is about an hour and a half north of New York City.  This to me indicates the start of this year’s flea market season.  What’s available at a non-hamfest flea market?  Well, my radio interests extend beyond Amateur Radio, so I always manage to find something interesting.  I have a small collection of antique transistor radios, and always look for new, and interesting samples.  I picked up a pristine Bulova MW/SW portable last year, which reminded me of a set I had as a kid.  It has been re-capped, and is playing rather nicely.  Some purchases I’ll admit end up on eBay eventually, after a good evaluation and cleaning.  The Bulova is a keeper though.

So, is there anything of interest to a Ham at these events?  For sure!  A smartphone with good internet service is a HUGE help at flea markets.  Quick lookups can tell you a lot about a prospective purchase.  Yesterday I saw a few items, including some test equipment, an SWR meter, and 3 boxes filled with commercial radios and accessories.  Watch the boxes under the edges of the tables for things like comercial radios, especially later this year when businesses and municipalities start dumping equipment that isn’t narrow-band compliant.  The box I found had 450 mhz (not convertible to 440 according to some quick research on the iPhone) and 800 Mhz equipment, but a nice collection of Yaesu and Icom chargers, and some remote speakers.  There was also a Motorola power supply for a mobile, a bunch of batteries, and a bag of about 30 HT antennas.  After talking to the proprietor the price dropped to $100 for all three boxes of equipment.  Reality struck though, and I passed on the lot, since I’m still sorting through the last pile of commercial radios I picked up.

Motorola JT1000 "Jedi"

As far as the Motorolas go, Watch for the VHF and UHF Jedi series radios.  Many of the Jedis can be reprogrammed for amateur use.  Ask around, and I’m sure someone you know through your club, or casual ham contacts knows how to program these.  It requires the correct cable (eBay) and the Motorola MTSX software.  Some of my fellow LIMARC members can attest to my fondness for the Motorola Jedi Series radios, which when successfully reprogrammed make a very nice 2 meter or 440 HT for event use, even if they are a bit heavy.  The batteries will last through a whole event, and then some, and the durability is legendary.  The common models to watch for are: HT1000, MT2000, MTS2000, MTX2000, JT1000, and MTX9000.  The JT model is a great find, since it is actually field programmable.  The 9000, is an inexpensive way to get on the 900 Mhz band.  If you grab one that cannot be reprogrammed for Amateur radio use, don’t fret!  Since most of the Jedis can be programmed to operate narrow band, they can be re-sold for commercial use, and usually at a nice profit.  More info can be found over at Radio Reference.

LIttle Tattler Headphones from oldheadphones.com

One booth had a nice pile of antique headphones.  I picked out a pair of Little Tattlers in fairly nice condition for $5.  These will be used for a crystal radio project for now after getting cleaned up. There were 2 fairly clean Hallicrafters receivers, both S-120s though, which don’t impress me enough to consider.

We headed home with the Little Tattlers, a very interesting old espresso pot, and a bag of wasabi peas.  Nice weather, good company, and an enjoyable hunt for interesting garb.  A successful morning.

–Neil W2NDG

Great weather here in Orlando for a good afternoon of QRP Portable. The QRP To The Field contest is always a good time to get out and give out a few more points to the serious contesters. I enjoy the concentrated QRP contacts and hearing my virtual friends once again. Every QRP event has a few regulars that are almost always heard. This year the bands were only so-so in Florida with lots of QSB on 20m which was by far the best for the day. It was solid at times and then signals would suddenly drop to the noise level which made RST reporting fun!

Mt. Cedar Tree: Just above sea level

Because of band conditions, I spent most of the 4 hours on 2om, but I did check 15 and 10m on an hourly basis. To do that, I pulled out my Ten Tec Argonaut 509 and used a Buddistick with the base up about 12 ft.  I called CQ about 50 times on 15 m but heard almost nothing on 10m all day. On 15m I heard a couple Eu  (IV4 and DK)  stations but was not getting a response to my calls and only heard 1 or 2 US stations so I assume the band conditions here weren’t quite right for those two bands.

Managed 18 QSO’s in 4 hrs of switching between my Wilderness Sierra to an EFHW, Delta Loop for 20m, and the Buddistick / Argonaut combo for 15 and 10m.  40 m was full of Florida QSO Party stations and a couple of nearby (within 4 miles) stations were pounding my receiver and causing the AGC to go nuts when I tuned across them so I only managed a single contact on 40 before retreating back to 20m.

I’ll be looking to give out more points in upcoming contests. So call CQ and I’ll be out there lookin’ fer ya!

72,

Kelly K4UPG

Buddistick on the way up

RFinder, the BEST repeater locator app on Android is now available in the iOS App Store. Bob has been working hard on getting approval for awhile now, and people like me who switched from Android to iOS have been waiting for this. If you’ve used any of the other available repeater apps and been disappointed, you really must try this one. Worth every penny at $9.99. If you’ve used Bob’s Android version you will be pleasantly surprised by the huge speed increase with the iOS release due to an upgrade to the database the app uses. Note to Android users: this will also speed up the original Android version on RFinder.

RFinder shows you all repeaters in your location in a selectable radius, or allows you to override the location for a custom search. Sorts by location, frequency, callsign, or displays on a map. Locates all repeaters in the database by band ( you choose which band or bands) 10M thru 1200. Corrections and additions can be submitted for paid users. Give it a try!

RFinder in the App Store. For iPhone and Ipad.

–Neil. W2NDG