The Amateur Amateur: Lessons in The Radio Facts of Life
By Gary Hoffman, KB0H
I like Mike, but his repeater drives me nuts!
May 17, 2002
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
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?
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.
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
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.
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
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.
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.
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?
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
As it happened,
the repeater had its own problems, but I'll let Mike tell that story
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
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.
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.
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.
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