[aprssig] power on DB9 connector standard for trackers?

Larry Cerney lcerney at viawest.net
Tue Nov 30 20:34:52 EST 2004


I tried to use the 78L05 on the open tracker which worked to power a Deluo
GPS.  The max I rating for the '05 is 140 mA and running the GPS (140 mA)
caused the 78L05 to get too hot for my liking.  So, what I did was to move a
7805 off to the side just for powering the GPS.  I took the input power from
the OpenTracker and connected the output of the 7805 to Pin 10 on the Jumper
Header which goes to Pin 4 of the DB9 connector.

Another option is to use the Garmin 18 with pigtails.  The Garmin 18 draws
~65 mA and could be easily powered from the OpenTracker's 78L05.  

I didn't go that route because after thinking about it I came to the
conclusion that it didn't make any sense to pay $80 to keep a $0.25 part
from burning up, duh....

BTW, I put the OpenTracker into a little Radio Shack project box, 2"x3", and
it fits great sideways with the DB9 connectors hanging out.  I drilled a
hole to put the power in through a grommet for strain relieve. I drilled a
little hole above the LED so I could see what the OT was doing.  Came out



"The only reason for time is so that everything doesn't happen at once." 
--Albert Einstein 
-----Original Message-----
From: aprssig-bounces at lists.tapr.org [mailto:aprssig-bounces at lists.tapr.org]
On Behalf Of Jason Winningham
Sent: Tuesday, November 30, 2004 5:59 PM
To: TAPR APRS Mailing List
Subject: [aprssig] power on DB9 connector standard for trackers?

Is there a standard for a tracker supplying power to a GPS via a DB9 

For example, the Opentracker has a jumper to pass Vin from pin 7 on the 
radio side DB9 to pin 4 on the GPS DB9, but this appears to be 

I thought I remembered a reference to a regulated voltage on pin 9, but 
I can't find it now.

It's not a big deal, but while I'm building a tracker housing and GPS 
cables, I figure I may as well adhere to a standard if there is one.


aprssig mailing list
aprssig at lists.tapr.org

More information about the aprssig mailing list