by James M. Jud, HOTARC Special Events Coordinator
The 2012 Waco Wild West Bicycle Tour finished today and in my opinion was a very big success. Our group did an excellent job with the communications and let me tell you, made HOTARC look very knowledgeable and professional. We covered ALL the Rest Stops, shadowed Rich Duhrkopf, the Rest Stop Coordinator, had eight SAG vehicles set up with APRS trackers, AND had three digipeters online for the trackers all while manning Net Control with three very competent Net Control Operators! Every race official I talked to was very happy with the communications and I even had two stop me to tell me this very thing! The people who helped on the race were:
Clint Anderson (AE5CA), Rodney Baden (K5YKC), Wayne Branscum (KD5SMC), Robert Buchanan (AF5CI, Ruth Bush ((KF5PGJ), Larry Carlson (AA5LC), Bill, Cox (W5JRM), Dave Cranfill (AF5CH), Bill Feltenberger (KD5UEW), Charles (Bud) Garretson Jr. (AD5SK), Ron Garrett (KD5TDY), Mike (Crash) Hancock (N5TCC), Ed Hynan (KC5KNI), Amy Oakley (KF5PGB), Brian (K5QZI), Elizabeth (W5EAS), and Keith Schoenefeld (w5TTL), Johnny Skinner (KF5NEP), Terry Williams (KD5KJU) and Glen Yerger (KD5BCM).
These people did the club proud and when you see one of these folks, tell them so! It was a pleasure working with these people! Hams always seem to come through when they are needed and this race, excuse me, tour, was no exception.
Using APRS for Special Events:
by Clint Anderson, AE5CA
2012 Waco Wild West Century Bike Tour
APRS Well-Received by WWWC
At the start of the WWWC Bike Tour, Keith Schoenefeld rode
along in the Lead Sheriff’s Vehicle. His APRS tracker, W5TTL-9 showed up on the
computer display in the Net Control Trailer. During the entire 100 mile ride,
we were able to know where the lead riders were because we could see the icon
from Keith’s tracker on our screen. We knew when riders would first be
approaching a rest stop, we knew about how fast the riders were progressing and
when the time came for the lead riders to cross the finish line, we knew they
were approaching and were able to get word to the MC so he could be prepared
for their arrival.
During the WWWC,
every few minutes, the SAG phone in the Net Control Trailer would ring. One of
the Net Control operators would answer it usually to find a rider who was broke
down, too tired to carry on, or who had missed a turn and was lost. We could
see who was closest to the rider’s location and call them to provide help.
At one point during the ride, Rich Duhrkopf, the Rest Stop
Coordinator, poked his head in the trailer and asked us to call the SAG vehicle
with tracker AE5CA-9 and ask him while he was in McGregor to stop, buy some ice
and take it to Rest Stop 5. He had been watching the progress of the APRS-tracked
SAG vehicles on his I-Phone and immediately knew that vehicle was in the
best position to help.
And toward the end of the race an APRS-tracked SAG vehicle followed
behind the last riders. So we and the race officials knew exactly where the “end
of the event” was.
APRS tracking provided a lot of useful information during
the WWWC. Knowing which SAG vehicle was the closest made it much easier for us
to dispatch help to a stranded rider. It helped move supplies to rest stops
that needed them. We knew the location of the lead riders. We knew when it was
okay to shut down a rest stop. We had an indication of how long it would be for
the last riders to cross the finish line.
What is APRS?
APRS stands for Automatic Packet Reporting System. One use
of a packet is to send GPS data to various sites that can utilize that
information. In this mode APRS is often mistakenly referred to as “Automatic
Position Reporting Station.”
An APRS Tracker typically consists of a
two meter transceiver, a GPS receiver, and some electronics to format the GPS
information and transmit it using the transceiver. All sorts of different
hardware are available for trackers—usually home-brewed by hams, but also built
right into many modern 2m rigs.
Most of the trackers we used during the WWWC were assembled
by Larry Bush, W5NCD. He built a number of trackers using Icom IC-V8 2m (5 watt) handhelds—putting
the printed circuit board of a Byonics
TinyTrak3 and 5V voltage regulator right into the V8’s battery pack cavity.
The TinyTrak audio and PTT cables connect right into the radio’s microphone and
earphone jacks. (See photo.) An external GPS receive unit and 12V power for the
radio and TinyTrak circuitry connect into a couple pigtails added to the radio
case. What makes this radio especially nice is that we can configure it to automatically
turn on whenever 12V is supplied—that is, when you start your car!
I also put together a couple of other trackers using available
radios, a TinyTrak controller and a GPS receiver. The cables between all of the
boxes turns out to be a mess, but it does work and we used two of these homebrew
trackers in this year’s WWWC. One used a hand held radio and one a mobile rig.
The handheld was actually a D-Star Radio. Really “overkill” for a basic
Kenwood now has several radios with the electronics to
perform APRS built-in right from the factory. Some only require you to plug in
a GPS receiver, and their latest handhelds even include the GPS! For that one, you
only need to set up the radio with your call sign, etc., and turn it on! That
described one of the trackers we used this year: my Kenwood TH-D72A handheld.
Several members of the club donated the use of their
trackers for the 2012 WWWC: Larry Bush W5NCD,
David Bush KC5UOZ, John Chamberlain AC5CV, Jim Jud KA5QKL, Keith Schoenefeld
W5TTL, and myself, AE5CA. So we had a record total of eight trackers involved
in this year’s WWWC.
Most APRS activity in the US operates on one frequency:
144.39 MHz. With this arrangement, you are almost guaranteed to be heard by
some APRS receiving station, and have your signals uploaded to the Internet and
the huge database of APRS signals. But, for special event applications, we don’t
want our frequent packets fighting QRM from all the other normal APRS activity,
or unnecessarily burden the rest of the APRS system. So, since we have a
sizable number of trackers, each making frequent position reports, we choose to
operate all the trackers on a different frequency for our APRS Network. However,
because of this decision, we need to supply our own infrastructure (not rely on
the national APRS network to manage all our packets).
Just as we use repeaters to extend the range of our voice
communications, we also use a special repeater to extend the range of our APRS
position packets. These repeaters that receive and resend digital radio
transmissions are called “digipeaters.” Instead of transmitting and receiving
the packet simultaneously on slightly different frequencies like our voice
repeaters, a digipeater listens for and records a packet, and then retransmits
it on the same frequency as soon as the originating station has completed its
transmission. In this way a basic two meter radio and a device to decode and
resend the packets is all the equipment required to operate as a digipeater.
As noted above, since we operated on our own frequency (not
the national APRS frequency), we had to provide our own repeater
infrastructure. To get sufficient coverage for the relatively low-power WWWC
trackers, we strategically positioned three digipeaters. One was located in
downtown Waco, on top of a nine story building. One was at my house in China
Spring, and the third digipeater was located at
Larry Bush’s tower site south of Waco.
The downtown Waco digipeater was a basic handheld radio
using the new TinyTrak4 controller
set up to provide the digipeater function. A power supply provided the 12 volts
to run the radio and TinyTrak during the Wild West. This provided fill-in
coverage downtown and in the Baylor area that in previous years had proved to
be a “blind spot” for our APRS coverage.
The second digipeater was run out of my home in China
Spring. This digipeater provided fill-in coverage for the extreme northern part
of the course. My home digipeater used my home 2m antenna, a two meter mobile
radio, a sound card interface and a desktop computer to provide the digipeater
functions. In addition, the software that provided the digipeater function was
also able to upload to the internet (i.e., serve as an internet gateway) the
information received from the other digipeaters and from stations it heard
directly. This gave us the additional ability to follow the lead vehicle and
SAGS using cell phones and laptops with internet access. This happens to be the
same radio and computer I normally use for Echolink, so the PC connections were
already proven. As it turned out, having the data uploaded to the Internet scored
big points for HOTARC this year.
The third digipeater is the one that really covers the lion’s
share of the course and serves as the wide area digipeater. Located at Larry
Bush’s tower near the Bruceville-Eddy area with an antenna up at 400 feet, this
digipeater nearly covers the whole course all by itself. In support of the WWWC
for the past several years Larry W5NCD takes his own 2m voice repeater off the
air during the WWWC and gives us the use of this wonderful antenna location. John
Chamberlain AC5CV, who routinely operates a digipeater out of his home, also
donates the use of his home digipeater for the WWWC, effectively relocating it
to the W5NCD tower for the day.
If someone else in the Club wants to start experimenting now
with digipeating, next year we might think about installing another fill-in digipeater
down near Mother Neff State Park—positioning some ears to listen down into the
river bottoms there. That was the only place on the course where we were unable
to obtain 100% solid coverage.
In the Net
Control Trailer, we wanted to see the position reports from each of our
trackers displayed on a map. To accomplish this we used APRSIS/32: a very well
written Windows software package for APRS. The normal set up is to use a 2-meter
radio listening on the chosen APRS event frequency to receive the APRS packets
coming from each tracker (usually via digipeater), and feed the audio into a Terminal
Node Controller (TNC) to convert the audio into a serial data stream. In this
case the powerful little Byonics TinyTrak4 served as the TNC, with a laptop
computer running APRSIS/32
displaying the results.
Using APRS for the WWWC
With APRSIS/32, I was able to preload the ride routes and
rest stop locations in the map. This gave us the ability to make sure the lead vehicle
was on the course, as well as knew when the lead or SAG vehicles were approaching
a rest stop. The APRSIS package also allowed for Tactical ID’s to be displayed
on the map. This meant that the real-time map showed the “SAG2” position instead
of “AC5CV-9.” Another feature of APRSIS is that it can pull down position
reports and messages from the APRS internet servers. Since our digipeaters were
uploading packets to the Internet gateways, computers and smartphones connected
to the internet were also able to obtain position reports. In the Net Control
trailer we also used that avenue as a backup plan.
As it turned out, this backup capability proved to be essential! On
the morning of the ride, when I set up the receiving station (computer, TinyTrak4, and radio),
I also connected the computer to the internet. I was glad to see all the trackers were
showing up on the display. I had good data. It meant the digipeaters were
working, and all the data was being sent to the internet, as planned. But I did notice a
problem: I was receiving data from the internet, but not over the air.
As you can guess, during the first couple hours of the ride, the Net Control
Trailer is a very hectic place! Since I had data showing up on the map, I chose to not worry about
where it was coming from (or NOT coming from!) for the time being.
After things calmed down a bit,
I searched for the problem with the radio. The radio was not hearing the
digipeaters, but it was obvious they were working since we were getting data
from all the trackers. Bad radio? I tried swapping radios...same result! So I chose to just be thankful
and rely on the Internet-provided data for our Net Control APRS display for the rest of the event. When we
took down the mast on the trailer at the end of the day, we discovered the
problem: the coax got snagged on something as we raised the mast, which pulled
the coax right out of the antenna connector. So, we essentially had NO
ANTENNA to the radio. Fortunately, with the unknown but serious antenna problem, it was fortunate
that our 2-meter APRS radio in the
trailer was only serving as receiver—not transceiver! Anyway, if not for our
data being ported to the Internet, we would have no APRS data available at
Net Control. Thankfully, Murphy did NOT win today!
comments I received from the WWWC officials was that the GPS tracking was very
helpful. They expressed a desire to equip all of the SAG vehicles
with a tracker next year. This year they had 16 SAGS. We were able to track 6
of them. Personally, I would like to see all of the SAG vehicles occupied by a
licensed Ham Radio Operator. Then Net Control can readily communicate with
every SAG vehicle via our radio net. When we conduct our next Technician Class,
I plan to recruit among the Bike Club members and other WWWC officials.
Viva la APRS!