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ZL3AI > APRDIG 20.02.04 20:00l 273 Lines 11591 Bytes #999 (0) @ WW
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To : APRDIG@WW
TAPR APRS Special Interest Group Digest for Wednesday, February 18, 2004.
1. Re: [aprssig] RE: [aprssig] RE: Mythbusters Cell phones Vs Gas Stations
2. Re: D-700 Questions
3.
=?iso-8859-1?Q?Re:_=5Baprssig=5D_RE:_=5Baprssig=5D_Mythbusters_=A0Cel?= =?iso-89
85-1?Q?l_phones_Vs_Gas_Stations_-_Liquid_Burning?=
4. KPC-3+ 512K RAM upgrade info
5. Re: Looking for historical APRS data to help with building coverage maps.
6. Details about KC8UCH APRS solar tetroon was RE: Balloon recovery pics
7. WIDEN vs UITRACE
8. high altitude balloon over Colorado.... update
9. Re: WIDEN vs UITRACE
10. High Altitude Balloon Flights
11. "Its just a hobby" (not!)
12. Excessive paths on balloons was RE: High Altitude Balloon Flights
13. Re: "Its just a hobby" (not!)
14. RE: Excessive paths on balloons was RE: High Altitude Balloon Flights
15. Re: Excessive paths on balloons was RE: High Altitude Balloon Flights
16. Re: "Its just a hobby" (not!)
17. Excessive paths on balloons was RE: High Altitude Balloon Flights
18. RE: Excessive paths on balloons was RE: High Altitude Balloon Flights
19. Coordinate question
20. RE: Coordinate question
21. RE: Excessive paths on balloons
22. Re: Excessive paths on balloons was RE: High Altitude Balloon Flights
23. Excessive paths on balloons was RE: High Altitude Balloon Flights
24. RE: Coordinate question
25. RE: Excessive paths on balloons
26. Re: Excessive paths on balloons was RE: High Altitude Balloon Flights
27. Amperage rating of cigarette ligher plug
28. Re: Amperage rating of cigarette ligher plug
29. Re: High Altitude Balloon Flights
30. Re: "Its just a hobby" (not!)
31. Re: Amperage rating of cigarette ligher plug
32. Alternate Balloon Paths
33. Re: Excessive paths on balloons was RE: High Altitude Balloon Flights
34. Tetroon construction?
35. RE: Tetroon construction?
36. RE: Excessive paths on balloons
37. Re: Amperage rating of cigarette ligher plug
38. Re: Amperage rating of cigarette ligher plug
39. Re: Alternate Balloon Paths
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Subject: Re: [aprssig] RE: [aprssig] RE: Mythbusters Cell phones Vs Gas Stations
From: Derek Koonce <derek@dkoonce.com>
Date: Tue, 17 Feb 2004 21:00:31 -0800
X-Message-Number: 1
I'd have to check my DOT (Department of Transportation) Hazard book, but
the fuel itself does not burn, unless, as stated earlier, high
temperature and/or pressure. It is the vapors that burn and can explode
when it is mixed with the right percentage of air/oxygen. My book is at
my other house and I can look up the details if someone wants the info.
However, I believe we are getting off the subject of this wonderful, and
informative, list.
Derek
KE6JTP.
Richard Amirault wrote:
>"...the ONLY component of gasoline that will burn"???? I think you meant to
>say the only component of gasoline that will *explode*. Liquid gasoline
>will burn just fine.
>
>Richard Amirault N1JDU Boston,
>MA, USA
>www.erols.com/ramirault "Go Fly A Kite"
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Subject: Re: D-700 Questions
From: "Antoine P. Cobb" <antoine@thecobbs.org>
Date: Wed, 18 Feb 2004 05:06:45 GMT
X-Message-Number: 2
(snip)
>>Number one: does the mute function actually work on this radio? I have
>>tried every combination of internal/external speaker combinations and
>>settings and the mute key does nothing except add the word mute to the
>>display.
>>(snip)
>
>As I understand it "mute" only _reduces_ the volume on the second half, not
>totally totally shut it down (and possibly only when the Main channel is
>receiving something)
Mute only reduces the receive only band when you are actually transmitting
on the transmit band. It prevents the input from one band from interrupting
you while you are transmitting on the other band.
--
Antoine P. Cobb, Esq.
Peoria, Arizona, USA
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Subject:
=?iso-8859-1?Q?Re:_=5Baprssig=5D_RE:_=5Baprssig=5D_Mythbusters_=A0Cel?= =?iso-89
85-1?Q?l_phones_Vs_Gas_Stations_-_Liquid_Burning?=
From: "Doug Younker" <dougy@ruraltel.net>
Date: Tue, 17 Feb 2004 23:28:21 -0600
X-Message-Number: 3
Gasoline in pool on the ground or in a "fire Bucket" *looks* like the liquid
is burning. I always figure it was the vapor soming off the liquid surface
that was burning. The heat create creates more vapor to burn untill the
liquid is finally consumed or the fire smothered.--73
Doug, N0LKK
dougy@ruraltel.net
----- Original Message -----
From: "Christensen, Eric" <CHRISTENSENE@MAIL.ECU.EDU>
: At STP it is the only component that will burn... For the liquid component
: to burn it has to be heated or the pressure must be high... If you are
: working in the temperatures or pressures at which gasoline liquid will burn
: I don't think you would be worrying about talking on the temperature... :)
:
:
: (STP = Standard Temperature and Pressure)
----------------------------------------------------------------------
Subject: KPC-3+ 512K RAM upgrade info
From: Derek Koonce <derek@dkoonce.com>
Date: Tue, 17 Feb 2004 21:33:38 -0800
X-Message-Number: 4
To make this brief, I'd like to let everyone know that I have a solution
to the 512K RAM upgrade for the Kantronics KPC-3+ - and be under $15. I
suspect it will work with the standard. I have been trying to let
everyone know. If you are interested I can repost with the solution or
will email separately.
Derek
KE6JTP
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Subject: Re: Looking for historical APRS data to help with building coverage
maps.
From: James Jefferson <jj@aprsworld.net>
Date: Wed, 18 Feb 2004 00:09:30 -0600
X-Message-Number: 5
>I thought, that if I could get a year or so worth of historical data, I
>could then plot every report on a map.. This map would then show every
>location where a signal did make it to an igate.. and give me a reasonable
>approximation of coverage.. Not perfect, but better then I've got now.
>
>So.. is there an historical archice of APRS reports?
Yeah, it's as simple as executing a command like this on db.aprsworld.net
SELECT DISTINCT latitude,longitude,altitude FROM position WHERE latitude>40
AND latitude <50 AND longitude>=-100 AND longitude <= -80;
If you give me a specific area I can run such a query for you.
This is how somewhat how I did the map of hops before igate in California.
-Jim
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Subject: Details about KC8UCH APRS solar tetroon was RE: Balloon recover y
picsFrom: "Rochte, Robert" <rrochte@gpacademy.org>
Date: Wed, 18 Feb 2004 11:31:08 -0500
X-Message-Number: 6
(Answers to questions posed by Bill Brown, WB8ELK, are below... Copied to
the list since others have asked similar questions and I haven't yet had
time to reply to all messages.)
>The balloon envelope looks intact.... a few minor patches
>and it could fly again....provided they figure out a way to
>get it out of the tree without ripping it. I imagine that the
>folks who live in that house would've seen it in a
>day or two....it was right on the edge of their clearing.
I doubt that we'll see a third flight out of that envelope - I was thrilled
to get two! Apparently the folks who live there haven't been home in a
couple of days... Jon Hampson has been trying to contact them, so far
unsuccessfully - he doesn't want to attempt anything drastic until he gets
their permission.
>I'd love some details on how you built the balloon
>envelope...thickness of plastic and where you got the
>material. Also, when you fly it...do you preheat the air
>inside or just let it sit outside until it warms up enough
>to lift off? How heavy was your payload and parachute?
>I notice that your previous balloon was black....and this
>one was clear....what differences did you see with
>using black vs clear?
>
> Did you use the primary Lithium AA's (like the kind
>available from Radio Shack or Wal-Mart) or were they rechargeable?
>
> It would be interesting to measure the air temperature
>inside the balloon in a future flight.
This tetroon used 9 micron high density polyethylene. I know, according to
conventional wisdom, high density is a big problem because of the high Tg
and all that - but it's now my fourth successful flight using it. And now I
can add traversing the jet stream in the dark (and thus without any solar
heating) to the list of accomplishments...
The tetroon was heated only by the sun - no external heat on the ground. I
am working on a ground-based burner to allow Bulle d'Orage type flights in
the future, but haven't yet used any type of heater. This tetroon was off
the ground in about five minutes - most of those five minutes spent fighting
a 5mph breeze that came up while I was rigging the payload box. I truly
thought that I was going to lose the tetroon - either to a shred thanks to
the breeze or to the nearby trees once I let it go!
The important thing for any solar Montgolfier is the relationship between
emissivity and absorptivity of the film. The black low density poly has
equally high values for each and so isn't terribly efficient. The clear
actually heats faster and flies higher. In the future, I will be using
aluminized biaxial nylon film - I'll have a small custom run done in the
next few months.
As an aside (particularly for other readers), it's worth noting that the
tetroon shape itself has no advantage over a natural-shape balloon other
than ease of fabrication. The Spirit of Piccard natural-shape took me about
30 hours or so to build, while the SD4 tetroon took about two hours. In
fact, it took longer to patch it after the first flight than to build it in
the first place! While the tetroon's volumetric efficiency is obviously
lower than a natural-shape, it is much better than either a pillow or
cylindrical balloon.
Several of my balloons have had temperature loggers suspended inside of the
envelope - the temp data that is on the Spirit of Piccard page comes from a
HOBO logger that was inside the envelope. A lot of this data has been used
to refine the current design (SD4 was actually an old design, built about
six months ago) and is part of a patent application - thus my reluctance to
publish it all to the web right now.
The batteries were Li/FeS primary cells (i.e., consumer-grade AA Lithium
batteries from Wal-Mart). Typically I use mil-surplus LiSO2 cells for my
payloads, but I opted for the easy way out this time.
All-up payload weight including parachute and rigging was just over three
pounds. Envelope itself weighed about two pounds including the integral
load ring (gone in the current design).
To recap for other readers: Payload consisted of Digitraveler GPS, KPC-3+
and Radio Shack HTX-245 mini-HT. Antenna was a ground-plane made from 18
gauge (I think - it might have been 20) copper wire. The payload box itself
was a small Sterilite (#1892 on this page -
http://www.sterilite.com/Category.html?Section=Storage&ProductCategory=42)
storage box, flipped upside down and sans handle.
There was also an audio beacon and alkaline 9v battery on the outside of the
box, but I forgot to switch the beacon on... (Alkaline used here so that it
freezes at altitude and thus doesn't beep again until it's near the ground -
cheap "altitude switch" that works every time.)
73,
Robert
KC8UCH
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