August 2013
The Amateur Amateur: Reseeding the Antenna Farm
By Gary Ross Hoffman, KB0H
In April of this year I lost most of my rooftop antennas to a storm (see
The
Amateur Amateur: Mastless in Missouri).
That was traumatic enough, of course, but even more stressful was the
hole in my roof. My main mast didn't go down without a fight. Prior
to the storm I'd had four VHF/UHF antennas up on the roof, plus two
scanner antennas, and also a stretch of wire connected to a SG-230
antenna coupler for HF operations. Three of the VHF/UHF antennas and
the SG-230 box were all on the same mast. It was too high. It weighed
too much. It wasn't guyed. And it came down.
That left me with one VHF/UHF
antenna and the two scanner antennas. I managed to re-purpose one of
the latter, so I was able to do my weekly ARES duties and still run
an APRS station (Automatic Packet Reporting System). That was better
than nothing.
Fortunately, my insurance company
was on the ball. They came out quickly, assessed the damage, and even
found old hail damage of which I wasn't aware. Rather than a
localized patch, they decided they'd pay for a whole new roof.
Wow! That was both good news and
bad news. I could've probably had the roof patched fairly quickly,
but getting a whole new roof meant a month-long wait, and I was
anxious to get more metal into the air. One of my two surviving masts
was mounted on a tripod. There wasn't much point in trying to put
anything else on that mast since it would all have to come down
before the roofers arrived. The other mast, however, was bolted to
the north eave of my house. I phoned the roofers and asked if I would
have to take it down as well. They assured me that I would not.
Okay! That gave me something I
could play with. As it happened, that mast held my oldest antennas,
two Radio Shack scanner discones, and a defunct anemometer. The
discones were somewhat beat up, having gone through a number of
hailstorms, and the home-made standoff connecting them to the mast
was my very first effort. Basically, everything on that mast needed
to come down anyway.
I wasn't sure exactly what I was
going to do. I figured I'd keep the discones, fix them up, and
replace the old RG-58 coax with something decent. The anemometer
could go, since it no longer worked. I thought maybe I could mount a
nice Diamond X50 in its place. Yeah, cluttered, but I have lots of
ideas and only a limited number of masts.
That project never took place.
Oh, I climbed onto the roof with my tools. I started unbolting the
mast. But when it came to pulling the base of the mast out of the
brackets on the eave, I realized that I would have to stand at the
very edge of the roof and wrestle with a lot of ungainly metal and
wire, all of which just might want to argue with me about exactly
where we were going to go.
And it was a
long way down to the ground.
I played it smart. I re-bolted everything and got down off the roof. By
ladder. I still wanted to remove that mast, but I needed to rethink
the whole process. I definitely didn't want to fall. I might just
survive, and then I'd be in
big trouble with my wife Nancy.
With the eave-mounted mast
project on hold, I needed to shift my focus. In fact, I needed to
shift the mast itself. Even if I managed to get it down, putting it
back up again would be just as terrifying. No, whatever I had planned
to put on the eave would have to go somewhere else. Could I jam
everything onto the tripod-mounted mast? Not a chance. I'd already
scheduled another clutter for it.
I needed a second tripod. And a
replacement for the one antenna that had busted when the old mast had
come crashing down.
Ah, spend money. Sounded like a plan.
I got out my sketchpad and drew a
picture of the roof-line with two tripod-mounted masts on it. I
figured that I could put a total of six antennas on them. Yes, I
know. That's too many RF sources too close together. But my coaxial
cables already had a very long route from my basement shack, through
various channels, zigs and zags, before popping out of an eave vent
and up to the roof. It's a compromise.
Did I actually have a use for six VHF/UHF antennas? Silly question! A ham
can
always find uses for
any number
of antennas! In my case it was: Two antennas for 2 meter voice, two
dedicated to 2 meter digital modes, one for 1.25 meter voice, and one
for a scanner. The only problem with that equation was that there
were just five decent coaxial cables running up to the roof.
Spend more money. It was for a worthy cause, right? And this time I opted to
get really high quality stuff.
The roofers came out in May and did their thing. The new roof looked so
pristine that it was almost a shame to put anything on it.
Well, I felt that way for about
ten minutes. After that I was itching to get up there and start
reseeding my antenna farm. I just needed two things:
- The presence of my safety officer (Nancy)
- A dry day
Oh yeah, it rained that May. In fact, it rained most of April, May, and June.
Especially on the weekends.
I can't remember how long I had
to wait, but eventually both Nancy and sunshine were available. I
scrambled up onto the roof and installed one of the tripods, a mast,
and a VHF/UHF antenna. Aaaaahhhh, it felt good to be back on the air.
At the next opportunity I
installed the second tripod, another mast, and a second VHF/UHF
antenna. The very next day I put a standoff halfway up the first mast
with two Diamond X50 antennas on it. The weather was cooperating and
I was on a roll.
With four antennas now up it was
time to assess their capabilities. Everything I had just erected was
lower than my original array, and I wanted to see how much that
affected my ability to send and receive.
I spent some time down in my shack testing everything and learned some
very interesting things. I could still reach most of the repeaters I
normally used, but my digital efforts were severely hampered. My
highest antenna could not reach any Winlink station and could only
marginally connect to the Missouri Emergency Packet Network.
Intriguingly, though, a
lower antenna with higher
gain
was able to get through. That was enlightening.
The higher antenna was a Diamond
D130J discone and the lower one was a Diamond X300A. (Okay, so I like
Diamond antennas.) I decided to put the X300A a bit higher and
connect it with the highest quality coax I could afford, 100 feet of
Bury Flex. So, down came the mast, the coax was switched, the mast
went back up, and....
Nothing. I couldn't get out on the X300A.
That was distressing. Not just
because something didn't work, but because it meant that I was going
to have to make additional trips to the roof. Either the new Bury
Flex coaxial cable didn't work (how could that be possible?) or I had
damaged my new X300A antenna. I didn't relish either scenario.
I put an ohmmeter on the Bury
Flex connector at the shack-end of the cable. Oh boy, there was a
short. And since I had purchased the Bury Flex with the connectors
already installed, I knew that I must have done something bad to my
expensive, brand-new X300A antenna.
I climbed back onto the roof and
took down the mast again. Not knowing what I could possibly do to
repair the antenna, I delayed the inevitable by finding other tasks
to perform. I disconnected the coax and gave it another test with the
ohmmeter.
Whoa, it
was the Bury Flex
that was shorted! That was inconceivable! I'd bought the cable with
pre-installed connectors because I knew that if
I installed
them, there probably
would be a short. It never occurred to me
that the vendor or manufacturer would pre-short the cable for me.
Analysis: The Bury Flex had a
short somewhere. It could have been at the shack-end connector, the
roof-end connector, or (shudder!) somewhere along the cable itself.
If it was in the cable itself I would have to remove the whole 100
feet of coax, something I really didn't want to do. It had taken
hours to route the blasted stuff.
Sighing, I started with the
shack-end connector. If that was the culprit, it would be the easiest
to repair. Cringing, I snipped it off. I put the ohmmeter on it, and
Yes! There was a short! Just to be sure that there weren't multiple
problems, I checked the rest of the coax again, and found no more
shorts. Whew!
I dug through my parts box, found
a fresh PL-259 connector, warmed up the soldering iron, and put the
new connector on the coax.
And it worked.
Somehow The Amateur Amateur had managed to do a better job than the
professional who had put on the original connectors. What a strange world we
live in.
Now I had just one final
multi-part task to perform before my antenna farm reseeding project
was done. I had to take down the eave-mounted mast, refurbish the
damaged discone antennas, yank out the ancient RG-58 cables and
replace them with better quality RG-8, stick the discones onto a new
home-built standoff and then mount it on a mast.
The only really significant part
of that task was to get the eave-mounted mast down without killing
myself. What I really needed was some way to keep the mast stable
while I unbolted it from the bracket on the eave. My tallest ladder
wasn't high enough to be of any use. I considered and rejected bucket
trucks, helicopters, mountain climbing gear and a host of other
wildly improbable schemes. And in the end I decided to use my most
dependable asset: Nancy.
Working
very slowly and
very carefully Nancy and I got the
eave-mounted mast down.
(How did I get it up in the first place?) I helped her get down from
the roof, then spent the next couple of hours taking care of the rest
of the tasks. It was tedious, but nothing untoward happened.
Everything works and I am happy. I learned a number of things. First, a
higher gain antenna may get a
signal out better than a physically higher antenna. Second, I should
always test my coax before routing it. Third, and most importantly,
you've just got to love a woman who will climb onto the roof with you
and help you with your insane schemes.
Shorted connector
Halfway finished
Eave-mounted mast, down and disassembled
The Farm Reseeded
One last job, cleaning up the cables
