MARCA - Motorola Amateur Radio

Pinal Peak ARA Work Project #5

We made a couple of trips to get the Packet digi radio network up and running properly at the Pinal Site.

Fixing the Digipeater Radio - The radio was putting out less than 1W.  The radio was taken down for repairs.  The following weekend, we returned with the radio fixed.  The radio was sensitive to battery votlage.  Radio was repaired and returned to the site the following weekend.  Unfortunately, the omni antenna is not functioning properly.  The SWR is poor.  18W out and 13 W return.  (Less than 5 W being transmitted.)

We still have to make a few more trips to Pinal -  to fix the Omni Antenna.  Anyone recommend a good reliable (inexpensive) antenna?

Backbone Link:
Marca has Pinal linked with a 9600 baud backbone to White Tanks Packet radio.
The White Tanks node is working when the temperature is just right.  It seems to like the hot desert days and not so much the cold winter days.

Here are some photos of the Pinal site.


Misty morning start. Cold. Hoping that we don't have to climb the tower.


The neighboring towe is impressive set of microwave links.


The MARCA back bone link antenna is a directional antenna near the bottom and
the MARCA omindirectional is just above the directional on the right.
The Omni is dual band - both UHF and VHF so that we can add a APRS station in the future.


Jim Gerwitz is peering through the ARA rack, getting setup to analyze the packet station.


Dave Hall taking notes.  Looks like the radio is not transmitting.


Fred Koehn and Paul Boyce looking over the station setup and staying out of the cold.


MARCA packet user node for Pinal and Globe, AZ


MFJ and Kantronics TNCs are used in the MARCA setup.


MARCA uses the guest rack -  relay box, duplexer and user node radio.


MARCA rack


We returned the following weekend and see that there has been snow on top of Pinal.
The Pinal site is very severe weather conditions for radio equipment since it seems to freeze and thaw more than at other sites.


The ARA repeater rack.


The ARA repeaters control rack.


The ARA repeater control rack backside.


The number 3 battery is cracked.  This 2 volt cell is in series with 5 other cells to provide backup power if the power mains go down.
The battery acid is leaking out and this battey will have to be replaced.


Cold on top.  Clear and sunny downstairs.


Dave checked the condition of the ARA batteries noting the measurements in the log.
The water in the cells wer about in the middle and they were topped off before leaving.


The ARA site is on the left.


The morning of the second trip was clear and sunny.  Snow on the tops of the mountain is still around from last weekend.


What a beautiful day on top.  A good start for the day.


Road up to pinal.  


Great scenery along the way.  Unusual tree greets visitors.


Great vistas all around Pinal near Globe, AZ.



Report by Paul Bennett
KD7KDO

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