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<DIV><FONT size=2 face=Arial>Hi Ted</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>There are at least two great Yahoo balloon
groups. Try posting you questions to one or both of these. There are
lots of folks that will be glad to help you.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><A href=""><FONT size=2
face=Arial>http://groups.yahoo.com/group/Ballooning</FONT></A><BR><FONT size=2
face=Arial> or</FONT></DIV>
<DIV><FONT size=2 face=Arial><A
href="http://groups.yahoo.com/group/GPSL">http://groups.yahoo.com/group/GPSL</A></FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>For our SABRE flights we fly two independent
trackers, both on 144.390. It doesn't always happen but two GPSs near to
each other can occasionally interfere with each other. Also be careful of
the path you use so as to avoid unnecessary interference especially in populated
areas like California. We have two hops in our APRS path because there's
very little APRS traffic here but that would be excessive where you area.
Your would probably want zero hops or one at the very most. Also be
careful of the transmit power. We run 300 mW and 500 mW and both trackers
are heard throughout the flight from 50 to 100 miles away. As far as
antennas go, we use a quarter wave radiator made from guitar string with one
counterpoise. The other tracker uses a dipole made from coax with the
shield pulled back over itself. For our vehicles we just use standard mag
mount antennas. A 5/8 wave will give you a bit more range when the
payload is on the ground, a 1/4 gives better coverage when it's in the
air. Both will have a null straight above the vehicle so you may
experience poor reception when you're directly below the payload. Outside
the vehicle, a rubber duck might be good enough. Aside from our two
redundant trackers, we run two milliwatt beacons on 220 and 440 MHz. We've
had more than one equipment failure but we've always had at least one method of
tracking function. (Except for SABRE-1. Check out the write-up on
our web page)</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>As far as power goes, Lithium batteries are the
only way to go. With reasonable insulation, the temperature inside your
payload should remain above freezing.</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>Good luck</FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>Bruce - VE5BNC</FONT></DIV>
<DIV><FONT size=2 face=Arial>SABRE - <A
href="http://ve5aa.dyndns.org/balloon">http://ve5aa.dyndns.org/balloon</A></FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial>----- Original Message ----- </FONT>
<DIV><FONT size=2 face=Arial>From: "Ted11" <</FONT><A
href="mailto:tedlists@hullar.com"><FONT size=2
face=Arial>tedlists@hullar.com</FONT></A><FONT size=2
face=Arial>></FONT></DIV>
<DIV><FONT size=2 face=Arial>To: "'TAPR APRS Mailing List'" <</FONT><A
href="mailto:aprssig@tapr.org"><FONT size=2
face=Arial>aprssig@tapr.org</FONT></A><FONT size=2 face=Arial>></FONT></DIV>
<DIV><FONT size=2 face=Arial>Sent: Friday, February 25, 2011 1:44
PM</FONT></DIV>
<DIV><FONT size=2 face=Arial>Subject: [aprssig] Balloon tracking
questions</FONT></DIV></DIV>
<DIV><FONT face=Arial><BR><FONT size=2></FONT></FONT></DIV><FONT size=2
face=Arial>> Hi everyone, <BR>> <BR>> I've gotten involved with a
high-altitude balloon project, and could use<BR>> some advice. An
undergraduate atmospheric science group from my university<BR>> (UC Davis, in
Davis, California) had its first launch last April. The<BR>> tracking
and recovery effort, although successful, was a little touch and<BR>> go, and
ultimately relied on GPS data provided by the meteorological<BR>> instrument
package. The primary cell-phone based tracking method failed.
<BR>> <BR>> So, this time around, I've offered to implement a better
tracking strategy.<BR>> I'm planning to use an APRS based tracker
setup. I'm familiar with the<BR>> Byonics and Argent tracker/radio/GPS
offerings, and understand the need for<BR>> a high-altitude GPS. What
I'm a little less familiar with are best<BR>> practices for power supplies
and antennas. I did a few searches (including<BR>> the APRSSIG archive,
but didn't come up with a lot of good information, so I<BR>> thought I'd ask
the group. <BR>> <BR>> Questions:<BR>> <BR>> 1. Is there
a dedicated balloon tracking list I should be sending my<BR>> questions
to?<BR>> <BR>> 2. Any recommendations for GPS, radio, and tracker
combinations? Any<BR>> particular combinations that do not work well
together?<BR>> <BR>> 3. What is the best approach for power?
I'm concerned about the extreme<BR>> low temperatures, especially in light of
some of the recent failures I've<BR>> read about.<BR>> <BR>> 4.
What do you recommend for antennas, both on the balloon and on the<BR>>
ground? I've got a VX-8DR I will be attaching to a roof mount antenna
on<BR>> the tracking vehicle, but wonder if there is a better approach to
match<BR>> balloon and receiver antennas. <BR>> <BR>> Thanks for the
help. <BR>> <BR>> Ted<BR>> KE6ROS<BR>> <BR>> <BR>> <BR>>
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