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ZL3AI > APRDIG 20.02.04 14:13l 239 Lines 9414 Bytes #999 (0) @ WW
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From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
Subject: RE: Excessive paths on balloons was RE: High Altitude Balloon Flights
From: "Christensen, Eric" <CHRISTENSENE@MAIL.ECU.EDU>
Date: Wed, 18 Feb 2004 16:13:36 -0500
X-Message-Number: 14
Robert,
I won't flame you but rather try to describe a picture to you in words (and
I'm not good with words)...
When your balloon is up floating at some high altitude with a path of WIDE,
then your balloon is going to be heard by hundreds (maybe even thousands) of
WIDE digipeaters. So they all give you balloon a little hop. Now would
probably be a good time to mention that your balloon is also being heard by
probably 75% of the APRS stations out there DIRECT (no hops from a
digipeater). So that first hop from the digipeater didn't do anything for
most that are quite close to the balloon (With quite a bit of distance from
the balloon, mind you. Remember that 2 meters is LOS or line-of-sight.
When you have a station that is up quite a ways then it is in sight for
quite a ways.) So you have most stations receiving the balloon directly and
then for those stations that have a compromised antenna system (like me) the
digipeaters are going to relay that packet again just to make sure that
everyone got it.
Probably the thing that you are missing is that not only is the digipeater
that is closest to you hearing AND relaying the packets but the all the
digipeaters AROUND that one are also doing the same thing. So when you run
a longer path than WIDE, then you are effectively causing QRM on the system
due to packets that were already relayed by ALL the digipeaters in that area
but are now relaying DUPLICATE packets from all the other digipeaters. So
the extra WIDE is not needed. The RELAY is definitely not needed because
that is not adding anything but QRM to the network. RELAY is ONLY used to
make it to the first WIDE digipeater in your area. Since the balloon will
be visible to MANY MANY WIDE digipeaters, it won't need the RELAY to make it
to one.
With this type of system, it would be very interesting to know how many
I-Gates the balloon was able to access during its' flight. I would think it
would have been quite a few! I hope this helps you see what is going on
with an extended path on your balloon.
73s,
Eric KF4OTN
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Subject: Re: Excessive paths on balloons was RE: High Altitude Bal loon
FlightsFrom: Vince <heffer@mindspring.com>
Date: Wed, 18 Feb 2004 16:50:01 -0500
X-Message-Number: 15
You have my vote!
Following your balloon was much more interesting than seeing someone's APRS
home, stationary mobile, or any station using Wide7-7 every few minutes :)
It seems that the guidelines are mutable and after being involved in a
'discussion' some months ago, few are interested in making the guidelines
known. So I sure as heck wouldn't worry about it.
For some it is a hobby, some take it to the extreme, some - like the sail
boaters in one class I monitored - find amateur radio necessary to ensure
survival. The boaters were not technically inclined, nor were they especially
interested in radio. But they sure were interested in APRS after they saw how
it showed their position.
It IS a hobby, have fun.
Vince
Rochte, Robert wrote:
>I haven't a flameproof suit, so I try to keep out of most "discussions"
>here... But...
>
>I think it worth mentioning, at least this once, that high altitude balloon
>flights seem to evoke more general interest in APRS than any other single
>type of special event.
>
>So perhaps the potential for QRM caused by excessive paths (and I'm assuming
>that my path of RELAY,WIDE,WIDE qualified as "excessive") on balloons is
>tolerable - maybe even *desirable* - given the attention that it calls to
>APRS.
>
>And not only to APRS, but to the many possibilities of this hobby, so few of
>which are even considered by the average ham.
>
>If I might be so bold, I would even suggest that a naughty balloon like mine
>just *might* have given more than a few APRS users their first actual reason
>to use that fancy Kenwood radio - or that software on their old PC - in a
>long, long time...
>
>With that, I'll run and hide from the flames - I'm afraid! =]
>
>73,
>Robert
>KC8UCH
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Subject: Re: "Its just a hobby" (not!)
From: Jeff King <jeff@aerodata.net>
Date: Wed, 18 Feb 2004 16:52:28 -0500
X-Message-Number: 16
I think you understood what I was saying, it really didn't have anything to
do directly with "radio". In other words, anything worth doing is worth doing
right, and that transcends "radio", "hobby" or whatever other label you might
want to stick on it.
As to who define's "right", you define right in your own mind. Now if you
want my opinion, as soon as someone say's "It's just a hobby" that is just
another way of saying one doesn't take things serious enough to do it right.
Fact of the matter is, I'd more expect that attitude in the workplace then in
a "hobby", which by definition is a labor of love.
As to the no-code debates.... a prescription of Thorazine would cure that for
the majority of participants.
--
Jeff King, jeff@aerodata.net on 02/18/2004
----------------------------------------------------------------------
Subject: Excessive paths on balloons was RE: High Altitude Bal loon Flights
From: "Robert Bruninga" <bruninga@usna.edu>
Date: Wed, 18 Feb 2004 17:09:17 -0500
X-Message-Number: 17
>>>"Rochte, Robert" <rrochte@gpacademy.org> 2/18/04 3:46:57 PM >>>
>I think it worth mentioning, at least this once, that high altitude balloon
>flights seem to evoke more general interest in APRS than any other single
>type of special event.
Agreed 100%. But why not do it right?
There have been hundreds of balloon flights with APRS and the lesson is
always the same. Use WIDE, and never ever use RELAY at any altitude,
whether a balloon, airplane or astronaut on 144.39.
>So perhaps the potential for QRM caused by excessive paths...
>on balloons is tolerable - maybe even *desirable* - given the
>attention that it calls to APRS.
I wouldn't go that far <wink>.
As I explained before, anything starting with RELAY is just down right
irritating to EVERYONE within 500 miles. Dont do it.
Beyond that, an abusive path of making it multiple hops is just a dumb
mistake, that doesnt hurt that much. But it doesnt INTERFERE with
communications in progress like RELAY does.
As I posted in my email about what RELAY does to almost every single
station, It keys them all up! Not only does this cause QRM on the APRS
channels, but at EVERYONE's HOME, CAR, or wherever there is an APRS
station, it QRMS and BLOCKS all use of the 2 meter band on ALL frequiencies
for the duration of that packet. That is just wrong, bad, inconsiderate,
and not desired, not appreciated and not to be done when there is no valid
reason for it.
Again, never-ever use RELAY as a path at altitude. The consequenceis are
far more than most people realize and we should not have to learn this
lesson over and over.
Again, Great project, and we LOVE balloons. And no real harm done. I was
just preaching to the masses in the above post, because many people just do
not understand the consequencies of some subtle things in APRS. So keep
up the good work.
Keep 'em coming...
de WB4APR, Bob
----------------------------------------------------------------------
Subject: RE: Excessive paths on balloons was RE: High Altitude Balloon Flights
From: "Christensen, Eric" <CHRISTENSENE@MAIL.ECU.EDU>
Date: Wed, 18 Feb 2004 16:55:31 -0500
X-Message-Number: 18
Absolutely! Have fun, but don't wreck everyone else's fun with horrific
paths that could bring a system down to its' knees. That is what these long
and unthought out paths do. So while you are beaconing along no one else
can get out!
73s,
Eric KF4OTN
-----Original Message-----
From: Vince [mailto:heffer@mindspring.com]
You have my vote!
Following your balloon was much more interesting than seeing someone's APRS
home, stationary mobile, or any station using Wide7-7 every few minutes :)
It seems that the guidelines are mutable and after being involved in a
'discussion' some months ago, few are interested in making the guidelines
known. So I sure as heck wouldn't worry about it.
For some it is a hobby, some take it to the extreme, some - like the sail
boaters in one class I monitored - find amateur radio necessary to ensure
survival. The boaters were not technically inclined, nor were they especially
interested in radio. But they sure were interested in APRS after they saw how
it showed their position.
It IS a hobby, have fun.
Vince
----------------------------------------------------------------------
Subject: Coordinate question
From: "Ken Cechura" <kcechura@umr.edu>
Date: Wed, 18 Feb 2004 16:26:46 -0600
X-Message-Number: 19
Is this the proper coordinate format for Rolla, MO?
(from GPRMC sting)
3757.6024,N,09146.0186,W
I'm HOPING APRS will play nice with this format... It's the only thing my
GPS will send... Or at least I hope there's a way I can make my KPC3 put me
on the right place on the map with it...
Thanks
Ken, KC9UMR
ENTIRE $GPRMC string:
$GPRMC,000012,V,3757.6024,N,09146.0186,W,0.000,0.0,290697,1.9,E*78
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