The Amateur Amateur: Lessons in The Radio Facts of Life

By Gary Hoffman, KB0H
Contributing Editor
May 17, 2002

I like Mike, but his repeater drives me nuts!

I like Mike. I've known him for a long time. Many years ago he organized our local police scanner club, and he's still the president. He also set up the SKYWARN operation in St Louis County. He encouraged members of the police scanner club to obtain ham radio licenses. He developed and taught a ham radio course. My wife Nancy and I were graduates of his first class.

Yes, I like Mike. It's Mike's repeater that drives me crazy.

Mike got his repeater going in early 1995. It was not new equipment. It was local-government surplus. Mike got permission to set it up at a friendly local electronics company, with its antenna about 30 feet up their huge mast. This was a nice central location, and the repeater cranked out about 90 W.

I was able to reach most ham repeaters around the St Louis area, so, given its location, antenna height, and power, I was surprised at how difficult it was to activate Mike's repeater. Not being one to simply say, "Oh well, that's just the way it is," I started trying to figure out why. Thus began some of my earliest lessons in the Radio Facts of Life.

The first lesson was simple enough. It was easier to reach the repeater if I was close to it. But sometimes I was quite near and couldn't reach it at all. Other times I was far away but could activate it quite easily. What was going on?

Discone police scanner antenna

A discone and cheap coax are fine for listening to the police scanner, but not too good for transmitting.

At the time, I was using a hand-held radio transmitting 5 W. I soon figured out that it worked better if I was outdoors rather than indoors. Okay, that made sense. The signals had to go through fewer obstacles. The same was true when I was in my car. I reached the repeater much easier if I connected my hand-held radio to an antenna outside of the car. Fine. An easy lesson.

The next lesson was a bit trickier. In fact, it led into a area of black magic that I still don't understand and on which I'm still working. The type of antenna made a big difference. I won't attempt to explain this one. It's a dark art and "that way leads madness." (As I understand this expression: Some people understand antennas very well, but they're all insane.) Anyway, the stunted little antenna that came with my hand-held radio was far from optimal. Using a more efficient antenna considerably improved the radio's range.

I eventually bought a mobile radio and installed it in my car. Now I had much more than the feeble 5 W of a hand-held radio, I had a blazing 50 W! I should be able to reach Mike's repeater from Kansas! And here came a lesson so perplexing and unbelievable that I couldn't convince anyone that it was true. Power didn't make any difference. If I couldn't reach the repeater with 5 W, I probably couldn't reach it with 50 W. The converse was also true. If I could reach the repeater with 50 W, although my signal might contain more static, I could probably reach it with just 5 W. As my aunt once said, "Radio is weird stuff."

Mike began a weekly radio net on his repeater, so I started trying to reach it from my home. I live at the north end of the county. Mike's repeater was in mid-county, and I could not reach it from my home. I tried sending and receiving through a police scanner discone antenna mounted on my roof and was able to reach the repeater about once in every twenty tries. Okay, another lesson: Height made a difference. Apparently when radio manuals and experienced hams talked about "line-of-sight" they weren't kidding. Remembering the lesson about the type of antenna making a difference, I ordered a "real" ham antenna (a Diamond X-50 dual-band) to replace my police scanner discone. I even added another 5 feet to the mast. These changes helped a little, but not much.

Diamond X50A

The Diamond X-50 2-meter/70-cm antenna was better for transmitting.

Hmmm. What was I overlooking? The feed line perhaps? I was using cheap coaxial cable to connect my radio to the antenna. It worked fine for the police scanner, but was it adequate for transmitting? I didn't know. I scrounged through whatever documents I could find and stumbled across something in Police Call, of all places. It was a table showing the relative signal loss in various types of coaxial cable. I found that up to three-quarters of my signal might be lost in the coax I was using! Whoa! Time to change feed line! I installed better (and, of course, more expensive) coaxial cable, and voila! I was able to reach the repeater from my home!

In the meantime, the electronics company lost a lucrative local government contract. Suddenly they weren't so friendly. Less than a week after I'd finally made solid contact with Mike's repeater, the electronics company pulled its plug.

Time passed, and Mike was able to find a new home for his repeater and get it going again. This time it was located a bit further from my house. I could no longer reach it, even with my fancy ham antenna and expensive coaxial cable. The propagation gods hated me. Back to square one.

Then an interesting thing happened. I attended a police scanner club meeting in which a member showed a couple of directional Yagi antennas that he had built. He described how easy it was to construct them and how much they improved the signal. He was talking about reception, but I knew that the same would be true for transmissions. The Yagis looked clean and neat and compact. Was it possible? Could I build my own Yagi? Would a Yagi help me to reach the repeater?

Home-brew Yagi antenna

Even held together with masking tape and a broomstick, the Yagi really gets the signal through!

More research. This time I found what I was looking for in The ARRL Handbook for Radio Amateurs. Yagi designs! Instructions! Yes, I could do this. I started looking around my basement for parts. I found everything I needed. This was just going to be a simple test device, nothing fancy. It didn't have to stand up to gale force winds. It could be made with duct tape, just so that it lasted long enough for me to make one successful transmission.

I was shocked to find that my completed Yagi was much bigger than the ones I had seen at the club meeting, even though it had the bare minimum number of elements. Ah, but the other Yagis had been designed to receive UHF and 800 MHz. Mine was designed for 2 meters. Anyway, I built the whole thing in just a few hours. It was ugly. It was crude. And it really was held together with duct tape. But I climbed onto the roof of my house with it, attached my hand-held radio to it, aimed it in a southwesterly direction, and transmitted. It worked! My signal was weak and scratchy, but it did activate Mike's repeater!

As it happened, the repeater had its own problems, but I'll let Mike tell that story another time.

All these experiments were done because Mike's repeater was so blasted hard to reach. But as Mike said, that's what Amateur Radio is all about. You are supposed to experiment, to fumble and fail, get up and try again, and eventually find a better way. Moreover, the repeater itself was Mike's own experiment in Amateur Radio.

The object was not to have a perfect communications medium. The object was to learn.

Reader Feedback

If you will recall, my previous column was about the problems my wife Nancy had when she tried to build a radio kit. Basically, it didn't work. After examining the kit and inspecting Nancy's work, I replaced a number of components. The completed kit then worked. I concluded that the problem was due to the components supplied with the kit--that they were out-of-range and had tolerances that were too wide.

I've been told by people far more knowledgeable than I that my conclusions, while intuitively logical, were probably incorrect. I say "probably" because one engineer said that if several components were way off the specifications, I might get the symptoms I had described. He said that a much more likely cause was that a component had completely failed.

Other people suggested that Nancy's (and later, my) soldering wasn't up to snuff. They described virtually undetectable bad solder joints that looked good but failed to make the necessary electrical connections. They said that such "cold solder" joints are quite common.

All of the electronically experienced people who wrote to me or whom I queried, told me that circuits usually will work to some degree, even if a component is fairly far off the desired value. I bow to their combined wisdom and accept that my conclusions were wrong.

I must add at this point that I received quite a number of messages from people who had just as much trouble with kits as Nancy and I had. Virtually every kit manufacturer was blamed at some point, although most had their fans as well. (Only those kit manufacturers that have long been out of business were remembered with universal fondness.)

So, there are a lot of us out there. Perhaps we're incompetent, perhaps we're victims, and maybe it's some mixture of the two. Who knows? There is no joy for us--the kit-building casualties.

Editor's note: ARRL member Gary Hoffman, KB0H, lives in Florissant, Missouri. He's been a ham since 1995. Hoffman says his column's name-- "The Amateur Amateur"--suggests the explorations of a rank amateur, not those of an experienced or knowledgeable ham. His wife, Nancy, is N0NJ. Hoffman has a ham-related Web page. Readers are invited to contact the author via e-mail, [email protected].

© 2002 American Radio Relay League


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