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ZL3AI > APRDIG 24.04.03 10:14l 257 Lines 10247 Bytes #999 (0) @ WW
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Subj: TAPR Digest, Apr 21, 3/7
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From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
Subject: UI-View32 on 486
From: Alex <kr1st@amsat.org>
Date: Mon, 21 Apr 2003 12:27:39 -0400
X-Message-Number: 19
Hi there,
I've been running UI-View (16 bit) on a new 486DX66-36Mb/Win95B machine
with a KPC-3 TNC for a while now and was wondering if the 32 bit version
would run ok on it. I'm using rather small, 60 kb, maps. I don't care if
it takes 10 minutes to start, I'm mostly interested if it runs ok after
it's started. I have ran UI-View many times before, but never for weeks
on end and I'm rather impressed by it. I never even bothered rebooting
the machine after I installed the 16 bit version. It's been humming
along ever since I installed it weeks ago. Pretty cool.
Thanks and 73,
--Alex KR1ST
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Subject: Re: Recommended Standalone TNC for APRS
From: Bill Vodall <wa7nwp@jnos.org>
Date: Mon, 21 Apr 2003 09:42:21 -0700
X-Message-Number: 20
>Why bother with a TNC and 2M radio? At a recent Hamfest, I saw D700s (in
>perfect shape) selling for $150, complete. Much smaller footprint, a dual
>band radio to boot, and the display has TONs of info on it.
As cool as the D700's are for APRS, (neglecting a few simple yet serious
shortcomings for the moment) their built in TNC, and the one in the similar
Alinco DR135, are not useable for serious packet data. You still can't
beat a decent stand along TNC or a soundcard modem setup.
73,
Bill - WA7NWP
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Subject: Re: WXTrak is now available
From: Bob Bruninga <bruninga@usna.edu>
Date: Mon, 21 Apr 2003 13:10:26 -0400 (EDT)
X-Message-Number: 21
On Mon, 21 Apr 2003, Byon Garrabrant wrote:
>>Bob Asked: Does it use the one-packet-tells-all complete WX format,
>>or require separate WX and Position packets which are less efficinent,
>>and guarantee that many users dont get the full report for quite a
>>while...?
>
>It does separate packets. I'd have to check my notes, but I think
>this was due to the Kenwood radios not decoding the tell-all packets.
Bummer. Its the opposite. Separate packets violate the fundamental
design objectives of APRS. The only reason the spec has positionless-WX
and WX-less positions for WX stations is because that is the way WinAPRS
wanted to do it. I was opposed from day one and still remain opposed to
that approach. Here is why:
1) APRS was designed to require no a-priori knowledge to decode and
understand the meaning of any packet (whre possible). Thus, everything
you need for information is supposed to be in one packet.
Positionless-WX and Weather stations sending WX-less-position data violate
this fundamental aspect of APRS.
2) Sending two packets where one will do is wastefull of channel
capacity. Especially considering all the AX.25 packet overhead of each
packet.
3) Sending POSITION data separately from WX data where the probability of
receiveing a packet (lets say X) is less than 100% (as in APRS) guarantees
that 1-X% of all receipients do not get the WX or do not know where it
applies until after they have received multiple packets...
4) Proponents of two-packet process attempt to Compensate for the wasted
air-time of #2 by reducing the frequency of sending the position to once
an hour or so.... But this means someone that does not know where the WX
station is apriori, then is denied the usefulness of the WX data by the
same time frame.
5) APRS is a real time TACTICAL SYSTEM. The position of a WX report is
fully and 100% a part of that report. The fact that some people like to
collect this data 24/7 via the internet and already konw where all these
stations are HAS NOTHING TO DO with the design of APRS as a protocol for
tactical-real-time come-as-you-are data system for use in the field.
6) In APRS, WEATHER was defined as an ATTRIBUTE to what is going on at a
given position. Weather data without immediate-in-the-same-
packet-position data is useless (in a tactical real-time system).
I have no complaints whatsoever about collecting this data 24/7 and doing
all kinds of great things with it, but if it is on 144.39, then every WX
packet should stand-alone and be usable on receipt (meaning it should
contain the position).
APRS was designed with 4 types of packets only:
Position: Can contain ANYTHING else going on at that location (WX)
Status: Can contain ANY kind of status that pertains to that stn
Messages: Short one-line tactical exchanges
misc prototol and others (Queries, etc)
Notice that OBJECTS are just a subset of position packets since they are
identical in format but only allow the name of the "object" to be
different from the station callsign.
Weather as originally designed in APRS is a position dependent phenomenon
and was designed to fit within a POSITION packet.
WinAPRS evolved as the Internet portion of APRS was gaining popularity and
many people were under the mistaken impression that watching the global
network of APRS via the Internet was the "basis of APRS design". THus,
they wanted to add a DATE stamp, County/NWS weather station name in every
WX packet for long term archiving of data. There was no room, so they
went to separate packets.
This added another problem:
* The time and date stamp in the positionless WX data format depends on
the reliability of individuals to set their clocks and dates correctly.
Experience has shown this to be unreilable. That is why APRS went to
TIME-STAMPS-ON RECEIPT for all tactical real-time data in the 1995/96 time
frame as the only way to collect consistent data. Or at least data who's
consistency was under the control of the "collecting station" and not
everyone else.
I could go on and on, but my position remains unchanged after all these
years. That is:
1) APRS is designed to be a tactical real-time distributed digital
communications system. It should not rely on any apriori information if
possible.
2) Positionless WX and Weatherless-position reports from weather stations
violate those fundamental principles.
3) All the bandaids to make the two work just require either more
bandwidth or result in greater latency in the real-time network.
I see no advantages to positionless WX and weatherless position reports
from APRS weather stations, but I can see all kinds of problems.
I am disappointed that this great new Weather Device was not designed with
the fundamental principles of APRS in mind.
de WB4APR Bob
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Subject: Cheap APRS radio?
From: "Ramon F. Kolb" <ramon@ieee.org>
Date: Mon, 21 Apr 2003 13:17:33 -0400
X-Message-Number: 22
Hi,
I'm looking for a cheap APRS radio to hook up to my TinyTrak, to replace my
2-mts portable that I'm using now. My requirements are, that it needs to run
on 12 Volts, have good enough audio quality, run a few Watts out on 144.390,
and have some kind of squelched audio out. Since it will be mounted out of
sight (under the rear seat of my car), esthetics is not important. Did I say
it had to be CHEAP?
Anyone have any hint what would work?
Thanks,
-Ramon
Ramon F. Kolb, KX1T, PA3EUG, Boston, MA, USA [FN42KI]
ICQ:77117744; MSNMGR:legalalien30@hotmail.com
http://kx1t.webhop.org
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Subject: Re: Cheap APRS radio?
From: David VanHorn <dvanhorn@cedar.net>
Date: Mon, 21 Apr 2003 12:27:39 -0500
X-Message-Number: 23
At 01:17 PM 4/21/2003 -0400, Ramon F. Kolb wrote:
>Hi,
>
>I'm looking for a cheap APRS radio to hook up to my TinyTrak, to replace my
>2-mts portable that I'm using now. My requirements are, that it needs to run
>on 12 Volts, have good enough audio quality, run a few Watts out on 144.390,
>and have some kind of squelched audio out. Since it will be mounted out of
>sight (under the rear seat of my car), esthetics is not important. Did I say
>it had to be CHEAP?
I'm very happy with my Yaesu FT-1500s.
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Subject: Re: WXTrak is now available
From: Jeff Brenton KA9VNV <ka9vnv@csrye.org>
Date: Mon, 21 Apr 2003 12:38:03 -0500
X-Message-Number: 24
>>It does separate packets. I'd have to check my notes, but I think
>>this was due to the Kenwood radios not decoding the tell-all
>>packets.
BB> Bummer. Its the opposite. Separate packets violate the fundamental
BB> design objectives of APRS. The only reason the spec has
BB> positionless-WX and WX-less positions for WX stations is because
BB> that is the way WinAPRS wanted to do it. I was opposed from day
BB> one and still remain opposed to that approach.
The genie left the bottle on this issue the minute DOS APRS supported
raw Peet Brothers packets on the air, which, I believe, predates the
WinAPRS positionless weather packets.
--
de KA9VNV
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Subject: Re: a few basic questions....
From: Bob Bruninga <bruninga@usna.edu>
Date: Mon, 21 Apr 2003 13:41:06 -0400 (EDT)
X-Message-Number: 25
On Mon, 21 Apr 2003, Alex wrote:
>>When you arrive at the scene and turn on your APRS station, a WX
>>report WITHOUT a position is USELESS!
>
>Heck, the whole concept of a WX report in this sense is USELESS (caps
>added for extra effect). When I arrive at the scene I think I pretty
>much know if it rains or not, or what the wind conditions are like. No
>need to turn on my APRS station and wait for an APRS WX report. :)
The purpose of WX reports in a tactical real-time event is to see what the
weather is "around" you. Not where you are. If a front is coming
through, the power is out, the lines are down, APRS tactical real-time
weather reports can show you what is coming or what just passed... or who
is currently affected and what areas are not.
Surrounding Weather in terms of HAM radio support of many local scenarios
is probably one of the most important aspects of many such events.
Watching the wind speed and direction of a WX station 10 miles west of me
gives me a very good idea of what I can expect soon...
If I dont know where it is, then the data is useless.
Bob, WB4APR
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