3 - Vincent Gap

Read all about the fun at Vincent Gap and then volunteer!

Click on photos for larger versions.

Location: The Vincent Gap AC100 checkpoint is Mile 13 on the race course and located at the trailhead to Mt. Baden-Powell. The elevation at Vincent Gap is 6565' and mile marker 74.8 on the Angeles Crest Highway (Highway 2). The sign says Vincent Gulch Divide. There are Forest Service vault toilets but no water or electricity.

Sign at Vincent Gap
Sign at Vincent Gap

Vincent Gap radio operators have 2 major challenges:
• Maintaining voice communication with Islip Saddle.
• WIND – in some years, there have been sustained 30-40 mph winds.

In 2005, 93 runners arrived in the space of 100 minutes. Since this checkpoint is so close to the start, runners arrive in large clusters. So we also have handle a rush of runners within a short time period, followed by waiting and waiting for the last runner to arrive at the next checkpoint. But not to worry! We take advantage of the waiting time to serve brunch, visit and enjoy the great outdoors!

Runners arrive from Inspiration Point on the east edge of the north parking lot, cross the highway and depart for Islip Saddle at the trailhead to Mt. Baden-Powell (the west edge of the south parking lot (by the vault toilets)). After leaving Vincent Gap, the runners climb to within 100 feet of the summit of Baden-Powell (elevation 9400') on their way to the next checkpoint, Islip Saddle, which is 12 miles and over 3 hours away by foot.

Runners heading to next checkpoint via Mt. Baden-Powell
Runners heading to next checkpoint via Mt. Baden-Powell

Radio Operations: Radio operators are stationed at 3 fixed and 1 roving locations. We use HTs using simplex for voice communication within the checkpoint. Power for the mobile radios and the packet computer is provided by two 75 amp and two 28 amp batteries. A minimum of 5 radio operators are needed for the 2 hours when runners are arriving and leaving. Having a 6th operator allows time for each operator to rotate among the stations and experience each part of the operations.

The packet station (using 220 MHz) and two tri-band mobile radios are located in a trailer parked on the western edge of the north parking lot. The packet station uses a laptop running Windows, a KPC3+ TNC, and a Kenwood mobile with a J-pole antenna mounted on the roof.

Starting in 2006, radio communication with the next checkpoint (Islip Saddle) using a low power HT was made possible by a "repeater in a box." This radio, battery, and antenna are placed on a ridge northwest of Vincent Gap where it is line-of-sight with Islip Saddle. Back-up communication via 2m Simplex with Islip Saddle is provided by a mobile radio (Kenwood TM641 tri-band) using 25 watts with an MFJ 2m ground plane antenna mounted on a 8' mast on a 3' tripod set in concrete blocks and lashed to the fence posts with bungee cords in case of wind.

View of “Repeater in a Box” from 5’ Away “Repeater in a Box” in its box MFJ 2m Ground Plane Antenna
View of “Repeater in a Box” from 5’ Away “Repeater in a Box” in its box >MFJ 2m Ground Plane Antenna

A second mobile radio (Kenwood TM742) is used for communication with Net Control via a Wrightwood repeater and 2m simplex communication with the previous checkpoint (Inspiration Point). This radio uses a Diamond tri-band mobile antenna mounted on a car parked next to the trailer.

One radio operator monitors the IN table, working with non-ham volunteers. Since the runners arrive in large clumps, we use special data forms that have one rowfor each minute from 0645 to 0930, with space for 20 minutes per sheet. One volunteer is responsible for watching the clock and calling out the time each minute. There are 2 teams (A team and B team) and 2 sets of data forms for recording the runner bib number and arrival times. One member of each team identifies and calls out the runner bib number while the other ember records the bib number in the appropriate time slot. As soon as each sheet is completed (every 20 minutes), it is taken to the packet station for packet data entry.

Another radio operator monitors the OUT table, working with non-ham volunteers in the same way as described for the IN table.

Early Morning at the OUT Table
Early Morning at the OUT Table

One radio operator circulates between the IN and the OUT tables to pick up the data sheets every 20 minutes and take them to the packet operator in the RV. This radio operator also keeps an eye out for race personnel who need to communicate with race personnel at other checkpoints or Net Control.

Expected Hours of Operations 0530 to 1410:
Our first official communications on race day Saturday start at 0530 when we verify communication with the previous checkpoint (Inspiration Point) and check in with Net Control and the packet database. We shutdown after the last runner reaches Islip Saddle. The cutoff at Islip Saddle is 1305, so we expect to be able to secure Vincent Gap around 1410.

Sunrise at Vincent Gap
Sunrise at Vincent Gap

Because of the 0530 startup, we set up the RV and antennas on Friday afternoon. We can then help put up and test the packet node on Frost Peak on Friday (hopefully before dark) and verify that the 2m ground plane antenna is located for optimum communication with the next checkpoint, Islip Saddle. Then, after dark, we listen for owls in the forest.

Race Day Communications Timetable:

0530: Inspiration Point radios on-the-air.
Vincent Gap packet on the air.
Check in with Net Control
0600: Complete voice testing with Inspiration Point (2m simplex)
Greet the Vincent Gap race coordinator
Recruit and orient non-ham volunteers to record runner IN and runner OUT times using our data sheets.
0615: Earliest possible voice/packet traffic from Inspiration Point
0630: Complete voice testing with Islip Saddle
0645: Earliest possible runner in at Vincent Gap.
0700: First runner expected at Vincent Gap.
0915: Earliest possible runner at Islip Saddle.
0920: Vincent Gap checkpoint runner cutoff.
: Brunch is served
1305: Expected last runner in at Islip Saddle.
1305: Islip Saddle checkpoint runner cutoff.
1410: Expected Vincent Gap checkpoint shutdown.

What to Bring: Radio operators should have an HT with 2 m and 440 capability and batteries for communication within the checkpoint. Dress in layers since it is cold early (particularly if it is windy) and hot later. Bring a hat, flashlight, sunscreen, and insect repellant. We have to bring our own food and water. The radio leaders have packet equipment, mobile radios, batteries, and antennas for communication between this checkpoint and the previous and next checkpoints, database, and net control. Clipboards, synchronized digital clocks, pens, data forms, chairs, and tables are provided.

Now that you’ve learned what we do, join us at Vincent Gap!