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ZL3AI > APRDIG 15.12.06 09:16l 269 Lines 10369 Bytes #999 (0) @ WW
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Subj: [APRSSIG] Vol 30 #10, 1/2
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From: ZL3AI@ZL2BAU.#79.NZL.OC
To : APRDIG@WW
Today's Topics:
1. RE: backup pwr systems (Robert Bruninga)
2. Four APRS satelites in orbit! (Robert Bruninga)
3. Four APRS satelites in orbit! WEB page (Robert Bruninga)
4. Re: Receive Only APRS (Jan T. Pharo)
5. Re: Four APRS satelites in orbit! (Peter Malacarne)
6. Re: Four APRS satelites in orbit! WEB page (VE7GDH)
7. Re: Four APRS satelites in orbit! WEB page (Bob Bruninga )
8. Re: backup pwr systems (Bruce Gordon)
9. Backup power (Bruce Gordon)
10. Re: backup pwr systems - slightly off-topic (Derek Koonce)
11. Re: Receive Only APRS (M J)
12. RE: backup pwr systems (Robert Bruninga)
13. mobil aprs software (flknbry)
14. Re: mobil aprs software (Curt, WE7U)
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Message: 1
Date: Sun, 10 Dec 2006 14:06:24 -0500
From: "Robert Bruninga" <bruninga_at_usna.edu>
Subject: RE: [aprssig] backup pwr systems
What I want, and no-one makes,
Is a 400 watt DC-to-Line synchronous inverter that can back feed into my
house power to save me a few pennies on the electric bill. It is a whole
lot of trouble to configure part of the house load to run on DC because
then you need a battery, and then you have to charge it during the day,
when no one is home and you don't need any DC, and they run it at night
after switching over to inverter. All of this takes work, effort, life
style changes, and none of it is worth the trouble for just a few hundres
Watts of excess green power.
But if there was a synchronous 400W inverter with just a line cord that you
could plug into any outlet in the house and if you had up to 400W of free
DC power available (wind or solar), then just plug this thing in, and it
would backfeed your existing circuits.
Of course it would be man-safe, and would only provide boost current only
if there was line voltage alreaady there. If there was no 60 Hz AC, then
it would do nothing.
What it WOULD do is reduce my electric bill during the PEAK summer rates
(time of use metering charges almosst 17 cents per KWH duing the summer
day). And it would do this with minimal effort, because the total
interface is just plugging it in. And I woiuldnt lose the battery
charge/discharge inefficiencies nor would I be wearing out my batteries
every day by cycling for this minimal power.
Think of it this way. There are dozens of stupid little "wall-warts"
haniging throughout my house that provide a constant drain on my electric
meter. The 5W of heat that each one is consuming is just not worth
re-wiring the house for DC, but the total of them adds up to probably a few
hundred watts 24 hours a day. By injecting my solar power during the midle
of the day when I get the most, into my mains, it would be like paying
myself 17 cents for every KWH I put in.
Again, do not confuse this with grid-tie inverters that are desigend to run
your meter backwards and which require Electric Company and all kinds of
approvals and all kinds of safety issues. This is just a small device to
help "reduce" my electric demand.
Anyway, it would be a dun design project for powering my 24/7 APRS system
and any spare power I have.
Bob, WB4APR
------------------------------
Message: 2
Date: Sun, 10 Dec 2006 14:45:33 -0500
From: "Robert Bruninga" <bruninga_at_usna.edu>
Subject: [aprssig] Four APRS satelites in orbit!
With the launch of STS-116, we now have just added a total of FOUR amateur
Radio Satellites on their way to orbit. These are in addition to the
PCSAT-1 and ARISS systems. So now is the time to play APRS satellites
while they last (it will only be a few months)...
ANDE MAA - packet digipeater and packet-to-voice
RAFT - packet digipeater and packet-to-voice
NMARS - Navy Marincorps Mars packet and Voice repeater
FCAL - Cubesat telemetry system
We call NMARS an amateur satellite too because it is operated by Amateur
Radio Volulnteers in the Military Affiliate Radio System. It is on MARS
frequency and only authorized MARS operators can use it, but they are all
duly licensed radio amateurs too.
These satellites will not last long due to their very low deployment
altitude, but they should provide a new opportunity to do experiments and
make packet contacts. This is especially true since ANDE, RAFT, PCSAT-1
all operate on the same frequency and can replay packets between
themselves. And if we are lucky, we might get the ISS to QSY to the same
frquency for a few 4-satellite experiments.
Bob, WB4APR
US Naval Academy Satellite Lab
------------------------------
Message: 3
Date: Sun, 10 Dec 2006 14:55:15 -0500
From: "Robert Bruninga" <bruninga_at_usna.edu>
Subject: [aprssig] Four APRS satelites in orbit! WEB page
Here is the Operations WEB page for these new satellites.
http://web.usna.navy.mil/~bruninga/ande-raft-ops.html
------------------------------
Message: 4
Date: Sun, 10 Dec 2006 22:03:28 +0100
From: "Jan T. Pharo" <la2bba_at_jpharo.net>
Subject: Re: [aprssig] Receive Only APRS
M J <mjandthegang_at_yahoo.com>, Sun, 10 Dec 2006 05:51:38 -0800 (PST):
>Is it possible to be a receive-only APRS participant? All I want to do is
>to decode what I can hear on my scanner and see it on my computer directly.
>I'm interested in a hardware device to do the decode if possible. IGWPE
>(did I spell that right?) doesn't interest me. Any opinions about choices
>available?
it's AGWPE :-)
You'll need a TNC (or a software-based equivalent, like AGWPE, decoding
packet radio) to see the messages; a piece of mapping APRS software to show
positions on a map. UI-View 16 bit will do the mapping part, and it'll run
without registration. <http://www.ui-view.org>
--
73 de Jan, LA2BBA
Hvaler, Norway
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Message: 5
Date: Sun, 10 Dec 2006 13:06:32 -0800
From: Peter Malacarne <peterm_at_telus.net>
Subject: Re: [aprssig] Four APRS satelites in orbit!
Yahoo!
------------------------------
Message: 6
Date: Sun, 10 Dec 2006 15:56:49 -0800
From: "VE7GDH" <ve7gdh_at_rac.ca>
Subject: Re: [aprssig] Four APRS satelites in orbit! WEB page
Bob WB4APR wrote...
>Here is the Operations WEB page for these new satellites.
>http://web.usna.navy.mil/~bruninga/ande-raft-ops.html
Interesting stuff! PS - the above page has a broken link to...
"Paper on RAFT's operation in the Amateur Satellite Service"
http://web.usna.navy.mil/pec/pec-itu.txt
I was going to say that it might be a DNS thing because I can't
browse to http://web.usna.navy.mil/ but I CAN browse to
http://web.usna.navy.mil/~bruninga/ande-raft-ops.html.
Umm... weren't mortals supposed to use the dot edu URL?
73 es cul - Keith VE7GDH
--
"I may be lost, but I know exactly where I am!"
------------------------------
Message: 7
Date: Sun, 10 Dec 2006 19:39:56 -0500 (EST)
From: "Bob Bruninga " <bruninga_at_usna.edu>
Subject: Re: [aprssig] Four APRS satelites in orbit! WEB page
>>Here is the Operations WEB page for these new satellites.
>>http://web.usna.navy.mil/~bruninga/ande-raft-ops.html
>
>PS - the above page has a broken link to...
>"Paper on RAFT's operation in the Amateur Satellite
>Service" http://web.usna.navy.mil/pec/pec-itu.txt
Ill fix that on Monday. This should work:
http://www.ew.usna.edu/~bruninga/ande/ande-itu.txt
http://www.ew.usna.edu/~bruninga/craft/RAFT-itu.txt
And the main page above should be:
http://www.ew.usna.edu/~bruninga/ande-raft-ops.html
Hope that helps.
Bob, WB4APR
------------------------------
Message: 8
Date: Sun, 10 Dec 2006 16:33:56 -0800
From: "Bruce Gordon" <bgordon_at_ltronics.com>
Subject: Re: [aprssig] backup pwr systems
Bob,
What you describe is exactly a grid-tie inverter, just not so large as those
used in all house or larger systems. I have never seen how they protect
themselves and others from the hazards of tying to the grid but I can't
think of a reason that it couldn't be done in a smaller unit. Might burn up
a little of that "copious free time" however.
Bruce Gordon
------------------------------
Message: 9
Date: Sun, 10 Dec 2006 22:18:14 -0800
From: "Bruce Gordon" <bgordon_at_ltronics.com>
Subject: [aprssig] Backup power
I have been involved with designing and installing standby battery systems
for many years. during this time, I have had the help of several experts in
battery design and have cleaned up the wreckage of too many systems that
used the "rules of thumb" recently suggested.
For a reliable installation:
Use only sealed "gel cell" or SLA batteries designed for float or standby
service. Flooded batteries require "equalization" to stir the electrolyte,
water replacement and better ventilation to minimize corrosion. (all should
have some ventilation.)
Temperature compensate the charging voltage if the battery temperature
varies by more than 10 deg. F. Get the voltage vs. temperature curve for
the specific battery you will use from the manufacturer. This may take some
digging. Be insistent! Most battery designers agree that departure from
the ideal curve by more that 50 mV either way AT THE BATTERY TERMINALS on a
12V battery will cut the service life in half! Isolation diodes will ruin
the regulation unless remote sensing is used. A typical charging curve
varies from 15.3V at 0 deg F to 13.3V at 120 deg F.
Provide a cutoff to limit the discharge voltage. The limit is commonly
around 10.5V for a 12 volt system. Again, get the data from the
manufacturer. Even a single "run flat" can seriously damage a battery.
Provide a current limit that prevents overheating of the charging supply
under low battery and high line conditions. Use a two stage charger only if
the time to recover the last 10 percent of capacity is critical. Never use
a 3 stage charger as "equalization" is unnecessary and can be damaging to
SLA cells.
If more than one battery in parallel is needed, use only batteries of the
same type from the same manufacturer and preferably from the same lot to
minimize unbalance and circulating current.
Results? How about our comm van, stored outside, which still has almost 90%
capacity after more than 7 years of continuous charging and use and no
maintainence using slightly modified Astron power supplies (not the Astron
mod). Prior to that, ordinary chargers and three sets of deep cycle marine
batteries lasted less than 2 years each, even with constant attention.
Bruce Gordon N6OLT
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