MARCA Inc.

White Tanks

27 Aug 2006 Site Visit

Site Details:

Arizona Repeater Association (ARA) is the Site Owner & Coordinator
- 146.940-  White Tanks VHF Repeater
- UHF Repeater

MARCA digital node for packet and APRS
- 145.710 VHF Packet 1200 baud node
- UHF Packet link to Pinal 9600 baud
- 144.390 VHF APRS
- 445.925 UHF APRS

Civil Air Patrol - Repeater & APRS tracking

Condor 220 MHz Repeater Link

Packet & APRS Maintenance Workday

August 27, 2006

MARCA Site Engineer:  Paul Bennett KD7KDO
ARA Site Manager: John Braden K7LKL

Volunteers:
Jim Gerwitz AC7FN
John Braden K7LKL
Lance Hall
Erv Heimbeck
James, ?, and ??

Issue:
- Packet station user node is not working.  It had a cold issue which has since gotten worse.

Work Assignment:
- Investigate status of station, packet and APRS.
- Bring Packet station back for temp cycling.

Observations:
- Power and lights on both TNCs were on, but only the DCD light on the link TNC was flashing.
- Remotely, Jim AC7FN was setup to test both Wtanks and Pinal packet station operation.
Jim could connect to the Pinal user node (1st try) and then connect through the TNC to the backbone -14 and thru to Wtanks -13 but not to the user node -6.  The node was busy.
Also Jim could not directly access the node -6.
- The user node TNC was power cycled.  The PTT was activated upon power up and then Jim tried connecting to it.  He immediately was able to connect to the -6 node directly, but still could not connect properly through the backbone.
- Next I powered down both TNCs and then removed and reseated both 25 pin connectors that connect between the two TNCs.  And repowered the TNCs back up.
- Jim could then connect and pass through the backbone as it should.  All systems appeared to be operational.
- It was still decided to take down both radios and TNCs for temp cycling.
- Upon removal of the units, it was noted that the crimp connection on the TNC of the user node was extremely poor and fell off the end.  This was likely the cause of the cold issue prior to the node not working at all.  Perhaps the TNC went "busy" because of the poor connection.
This will need to investigated further.  Both packet radios and TNCs were brought down the mountain.


Lance Hall, ARA MS150 check-out.  All systems GO!


New startup battery in generator.  Backup power tested.  All systems operational.


MARCA packet user-node TNC.  Crimp connector on positive terminal .. gone.


Link cable between TNCs needed reseating before link between TNCs was completely
operational.  (Note: check from both ends of the link.)

James and John discussing the various antennas located on the tower.


The tower.


The front side of the MARCA rack.
Top: The packet station has been removed.
Middle: An APRS UHF digipeater.
Bottom: An APRS VHF digipeater.


The back-side of the MARCA rack.


Closer up view of the APRS digis.

Lance, Erv and Paul checked out the APRS radios using the command mode of the TNC
and a service monitor.
The power of the VHF APRS was 22W, 3 KHz deviation and -50 Hz.
The power of the UHF APRS was 20W, 1.7 KHz deviation and -500 Hz.
No adjustments to the radios were made although the deviation of the UHF station is a bit low.


Time to head back down the mountain road
... it was a short day; it is only 11:00 AM.

All things at White Tanks check out for the MS150 event.

Thanks go to Jim Gerwitz, AC7FN, for helping me test and debug the packet radio rack.

written 27 Aug 2006

back to Paul's MARCA webpage
back to Bennetts webpage
back to Arizona Croquet Club