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ZL3AI > APRDIG 13.12.06 23:21l 192 Lines 6883 Bytes #999 (0) @ WW
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Subj: [APRSSIG] Vol 30 #8, 1/1
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From: ZL3AI@ZL2BAU.#79.NZL.OC
To : APRDIG@WW
Today's Topics:
1. Naval Academy APRS Satellites (Robert Kirk)
2. RE: Naval Academy APRS Satellites (Robert Bruninga)
3. Re: backup pwr systems (Chris Rose)
4. Re: backup pwr systems (Joe Della Barba)
5. Re: backup pwr systems (Dale Blanchard)
6. Re: backup pwr systems (tg)
----------------------------------------------------------------------
Message: 1
Date: Fri, 08 Dec 2006 13:20:19 -0500
From: Robert Kirk <isobar_at_bcpl.net>
Subject: [aprssig] Naval Academy APRS Satellites
I saw this nice press release below from the Naval Academy.
The only problem is that APRS got second billing to those silly, supposedly
primary missions :-)
(Last night's launch was postponed because of wx; hope they make it ok on
Saturday.)
Bob Kirk
N3OZB
>THREE U.S. NAVAL ACADEMY SATTELITES TO LAUNCH DURING UPCOMING SHUTTLE
>FLIGHT
>
>ANNAPOLIS, Md. - Three satellites with systems designed, built,
>and tested by Naval Academy Midshipmen at the Academy's Satellite
>Laboratory will be launched into orbit by Space Shuttle Mission
>STS-116. The shuttle is scheduled to launch tonight. [Thursday]
>
>After completion of STS-116's mission to the International Space
>Station, the Shuttle will deploy the Naval Academy satellites, Radar
>Fence Transponder (RAFT), Military Affiliate Radio System
>Communications (MARSCOM) and Atmospheric Neutral Density Experiment
>(ANDE). These satellites were designed, built and tested by
>Midshipmen in the Classes of 2003, 2004 and 2005 under the supervision
>of Senior Research Engineer Robert Bruninga as a part of our aerospace
>engineering program. Current Naval Academy Midshipmen are working on
>the next generation Academy satellite, PARKINSONSAT.
>
>The primary mission of the RAFT satellite is tied to the calibration
>of the Department of Defense's Space Surveillance Radar which is a
>major source of satellite tracking data for all spacecraft in the U.S.
>This radar helps generate the tracking data used by most satellite
>tracking systems worldwide. The MARScom satellite is similar to RAFT
>but operates on Navy-Marine Corps MARS frequencies for volunteer
>Department of Defense communications experiments.
>
>The secondary mission of RAFT and MARScom is to provide a digital
>communications relay for mobile units to transmit their GPS
>coordinates and messages via the satellites. This is a continuation of
>the Naval Academy's previous Prototype Communications Satellite and
>PCSAT2 missions. The downlink is made public in accordance with the
>rules of the International Amateur Satellite Service, and is received
>by a global system of volunteer ground stations that feed the live web
>page network: http://pcsat.aprs.org.
>
>ANDE was developed by the Naval Research labs as an "Atmospheric
>Neutral Density Experiment" to measure the decay from orbit of a
>perfectly spherical 19" ball. Upon learning that the sphere would be
>empty, the Naval Academy proposed an amateur radio transponder for the
>inside. Since there could be no external antennas, solar panels or
>anything that would disturb the aerodynamic performance of the very
>smooth sphere, Bruninga suggested that the spherical satellite be
>split in half with an insulator. The resulting space frame could then
>be used as the antenna for the VHF system. There are 112 Lithium "D"
>cells inside the sphere to power it for a year.
>
>Chairman of the Naval Academy Aerospace Engineering Department,
>Professor Daryl G. Boden said, "The Aero Department is extremely proud
>of the midshipmen who have contributed to this effort and of Bob
>Bruninga, who never ceases to amaze me with what he can accomplish." [!!]
>
>The information from these satellites will be similar to that of
>previous Naval Academy satellites and will be distributed by the
>network of volunteer ground stations to feed a central live telemetry
>Web site http://pcsat.aprs.org. This makes the downlink valuable for
>students and educators because it will be available on a "live" basis
>more often than just the few eight minute passes per day that each
>single station might receive alone.
>
>For technical details on the Naval Academy satellites, see the
>ANDE/RAFT operations web page:
>http://www.ew.usna.edu/%7Ebruninga/ande-raft-ops.html
>
>USNA
------------------------------
Message: 2
Date: Fri, 8 Dec 2006 14:46:46 -0500
From: "Robert Bruninga" <bruninga_at_usna.edu>
Subject: RE: [aprssig] Naval Academy APRS Satellites
Bob,
Thasnk!
Bob
------------------------------
Message: 3
Date: Sat, 9 Dec 2006 07:32:16 -0800 (PST)
From: Chris Rose <kb8uih_at_sbcglobal.net>
Subject: Re: [aprssig] backup pwr systems
Leaving a battery constantly plugged in to a charger will cook and kill the
battery. I have ruined more than one. I don't suggest that course of
action. Having a battery available to connect to when mains go down is a
better way to go. Some circuits are available to show how to do this.
Some simple and some quite elaborate depending on how many raidos or
scanners you have to take care of.
Chris
KB8UIH
----- Original Message ----
>From: Ben Lindner <vk5jfk_at_activ8.net.au>
>To: TAPR APRS Mailing List <aprssig_at_lists.tapr.org>
>Sent: Sunday, December 3, 2006 5:45:53 PM
>Subject: [aprssig] backup pwr systems
>
>Hi all,
>
>What sort of backup power systems do people use these days. ?
>
>eg.
>
>Running a rig from a standard PSU while charging a battery at the same
>time and when the mains power drops out the battery will take over and
>run the radio. Then when the mains power is returned every thing is back
>to normal, battery is charged again from PSU and radio runs from PSU.
>
>Any body have any ideas on how to work this or has a circuit that I can
>build
>
>Ben Lindner
>VK5JFK
------------------------------
Message: 4
Date: Sat, 09 Dec 2006 10:58:01 -0500
From: Joe Della Barba <joe_at_dellabarba.com>
Subject: Re: [aprssig] backup pwr systems
You need a battery charger designed for this service. Most any marine
hard-wired battery charger is designed to run all the time. Look for a
"3 step" or "smart charger".
73
Joe N3HGB
------------------------------
Message: 5
Date: Sat, 09 Dec 2006 08:32:03 -0800
From: Dale Blanchard <wa7ixk_at_earthlink.net>
Subject: Re: [aprssig] backup pwr systems
With the proper smart charger it is ok to leave on all the time.
Cheap trickle charger can kill batteries.
Dale
------------------------------
Message: 6
Date: Sat, 9 Dec 2006 08:58:17 -0800
From: "tg" <wd6dfh_at_hughes.net>
Subject: Re: [aprssig] backup pwr systems
Something like this. Have been using one for about two years without any
problems.
http://www.iotaengineering.com/dlm15.htm
Todd wd6dfh
------------------------------
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