MARCA - Motorola Amateur Radio
Mt. Elden
September 21, 2003
Packet Radio Antenna Repair
Coordinator/Climber: Dave Hall N7ZPY
MARCA has a packet repeater.
MARCA's four volunteers - Dave Hall N7ZPY, Jim Gerwitz AC7FN, Paul Boyce
KJ7KY and Paul Bennett KD7KDO.
Mission
-- Remove old antenna and brackets.
-- Run new 1/2" heliax.
-- Mount bracket with top stay.
-- Mouint new antenna.
-- Install ground kit.
Dave Hall, Jim Gerwitz and Paul Boyce
Done with a good breakfast at Mike and Rhonda's in Flagstaff and ready
to head up to the mountain.
On the road heading up Mt. Elden (background). Our antenna is located on
the left most tower.
We share the tower with its owners - the Arizona Repeater Association.
The view on top is beautiful. The tower is just around the corner.
The backside of our tower and a large communications tower nearby.
Inside the building are ARA repeaters and MARCA's packet link.
The operation today is to remove the old brackets at the middle on the
back side and install our new comet antenna in its place.
Roll out the coax and attach the connector to the 1/2" heliax.
Dave Hall climbing the tower.
Dave readys the hauling system.
Dave making the last few adjustments to the top bracket.
Jim making the coax connection inside with Paul.
Paul marking the new coax and testing the SWR.
Grounding kit installed and the coax leading into the building
sealed with silicon. Notice the ice bridge above the cables and the
grating overtop the building to help prevent ice sicycles from sheering
the coax during the spring thaw or piercing through the roof of the building.
The new MARCA antenna is on the right, tested and operating.
The forward power out measured 28 W. The return power
measured about 4 W. The SWR = (1+ratio)/(1-ratio) = 1.33 where the
loss ratio equals 4/28. The SWR is a bit high since the radials we
took up were too small to fit the antenna.
Flagstaff down in the distance.
You can see out pretty far ... on a clear day.
The wives have collected some pine cones for holiday decorations
while the boys have been busy playing with the radios.
Afterwards, we head down the mountain and back to Phoenix. We meet
up again in Rock Springs Cafe for a bite to eat and a slice of pie. We
were a bit hungry after coming down the mountain and waiting in traffic to
clear for an accident near sunset point.
Report by Paul Bennett, KD7KDO.