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ZL3AI > APRDIG 13.07.03 14:39l 226 Lines 9182 Bytes #999 (0) @ WW
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Subj: TAPR Digest, Jul 10, 3/4
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From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
Subject: Re: APRS on PocketPC users?
From: "Mark Fellhauer" <sparkfel@qwest.net>
Date: Thu, 10 Jul 2003 12:28:27 -0500
X-Message-Number: 18
At 06:17 AM 7/10/2003, Mike Yetsko wrote:
>I haven't kept up with the Poquet PC for a while, but I do NOT believe
>there are any OS setups for the thing that would virtualize the com ports.
I'd just like to point out there's a difference between a computer running
some form of Embedded Windows (WinCE, Pocket PC 2002, Windows Mobile 2003)
- that is a POCKET PC and the Poquet (SIC) PC.
The Poqet is a small computer the size of a VHS video cassette and runs
embedded DOS 3.3 or 5.0 on an XT compatible processor to a small MDA or CGA
compatible screen. I believe the maximum amount of memory they came with
was 2MB of RAM. There's probably two of them in my garage somewhere -
in pieces (Poqet PC Plusses). The Poqet was a marvel in it's time (1989),
but was always way too fragile and flimsy. My Casio A-11 of a few years
later (WinCE 1.0/2.0) OTOH was comparatively quite tough.
http://www.bmason.com/PoqetPC/
Mark
KC7BXS
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Subject: Re: Don't know how many people noticed this
From: Doug McFadden <kc7imr@orednet.org>
Date: Thu, 10 Jul 2003 11:35:20 -0700 (PDT)
X-Message-Number: 19
On Wed, 9 Jul 2003, Sean \The RIMBoy\ wrote:
snip ><..........
>
>>What's the incentive, with the 'net being so ubiquitous and cheap?
>
>For HF or for code? I can honestly say the few QSO's I've had on HF have
>been worth it. I've been excited making the contact and excited after the
>end of the QSO. I'm sure it will wear off, but it's been fun the few
>times I've been on.
>
snip ><..........
Why don't you start a HF net to talk about APRS & related???
Doug/KC7IMR
Trying to establish voice contact ... please yell into your keyboard.
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
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Subject: today's test results
From: wes@johnston.net
Date: Thu, 10 Jul 2003 15:14:57 -0400 (EDT)
X-Message-Number: 20
Today I ran a test with the help of kc4pl. We set our kenwood d700s up to
transmit once a minute while stationary. Discussions from previous days had
suggested that multipath and picket fencing was causing packets to not be
decoded. To establish a baseline, I wanted to see just how many packets were
lost when the band conditions were constant. I did this with stationary
vehicles to remove the possibility of picket fencing. Yes, airplanes could
still fly overhead and cause variations in multipath and signal strength
variations.
kd4rdb's mobile. 60 second posit rate. Stationary
20 mile raduis 3 stations
30 mile raduis 10 stations
50 mile raduis 20 stations
31 lost out of 150.... Hipower 20% <-------------
37 lost out of 90... low power 41% <-------------
kc4pl's mobile. 60 second posit rate, Stationary.
20 miles 11 stations
30 miles 11 stations
50 miles 16 stations
50watts 21 lost out of 128 16% loss <-------------
5 watts 21 lost out of 84 25% loss <-------------
By nature of the fact that our success rate went, but we still got in some
of the time when we switched to low power says that our local digipeaters
CAN hear us on low power, but other digipeaters and stations around are not
hearing us and stomping on our packets. If a single digipeater can hear me
then I can get into the network. However, other digipeaters must also be
able to hear me so they don't transmit over the top of me. Losses on my
station run between 20 and 41 percent. I'm in a hole where only one
digipeater can hear me, and it's the IGATE. The result of this experiment
is that if you run higher power in a mobile, distant stations still may not
be able to decode you... but they'll hear you well enough so that they
don't TX on top of you - or the FM capture effect keeps the digi listening
to you instead of the others. This is contrary to good operating practice
in ham radio which says use the lowest power possible to establish
communications.
Now I have a standard range of values to use when estimating losses
attributed to hidden transmitter problems. These numbers can now be
compared to moving vehicles to calculate the losses associated with
multipath and picket fencing. As it stands, we have two stations which have
a 59% to 84% chance of getting a valid posit into the network when they are
sitting still.
****************************************************
Notable findings today include the fact that if a digipeater (be it a relay
or a WIDE) runs energy detection type carrier detect, then that digi could
queue packets for several minutes. If that time period is longer than your
beacon interval, your car will appear to jump around. There are two
solutions to this... encourage all digi owners to run true DCD or in the
case of kantronics, CD SOFT, or transmit the time with your packets so that
software can later resort the packets if they come in out of order.
If you own a digpeater in a location which is subject to bouts of
interference from pagers or front end overload, please run true dcd or CD
SOFT !!
Wes
ham callsign: kd4rdb
find me: http://wesvan.zapto.org
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Subject: Weather software
From: kb2scs@optonline.net
Date: Thu, 10 Jul 2003 15:54:35 -0400
X-Message-Number: 21
Hi All
What is the name and the URL of the stand alone weather software that takes
your home weather stations output and turns it into a format that APRS
client software can use and send out on the air.
Thank you in advance for the help.
Let us hope we never witness the "Silence Of The Hams"
73 DE John KB2SCS
Mail To: kb2scs@wa2pnu.#nli.ny.usa.noam
E-Mail: kb2scs@arrl.net
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Subject: RE: Weather software
From: "John Bruckner" <jbruckner@cox.net>
Date: Thu, 10 Jul 2003 15:04:41 -0500
X-Message-Number: 22
Weather display. http://www.weather-display.com/
73, John W0HII
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Subject: Re: today's test results
From: "Mark Fellhauer" <sparkfel@qwest.net>
Date: Thu, 10 Jul 2003 15:18:00 -0500
X-Message-Number: 23
At 02:14 PM 7/10/2003, wes@johnston.net wrote:
>Today I ran a test with the help of kc4pl. We set our kenwood d700s up to
>transmit once a minute while stationary. Discussions from previous days had
>suggested that multipath and picket fencing was causing packets to not be
>decoded.
You forgot other differences in equipment and environment which can affect
packet success. Mutltipath and picket fencing are but two.
When I used to work in North Sioux Falls about 3 miles from the digi, I
would park with a large metal building between my car and the digi. Logic
dictates that a large metal building would block the signal - and it did,
about 90% of the time (even at 50 watts). Some days though, I would be
able to have almost a 100% digipeat rate from that parking lot (even at 15
Watts). Go figure... And it didn't seem to have any rhyme or reason -
didn't follow band openings or anything like that.
OTOH, I have travelled to other cities, like Minneapolis, where there seems
to be no cooperation/coordination of who digipeats and when, so it ends up
everyone and his uncle is digipeating - even from homes and from
mobiles. The packet cacophony caused by this is utter nonsense...
I once accidently left digipeat on at my home QTH when I lived in Phoenix.
I got a phone call within 4 hours politely asking me to stop... :)
Mark
KC7BXS
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Subject: Thoughts? on hidden transmitter
From: "Jerrold Billmyer" <jerrold@carr.org>
Date: Thu, 10 Jul 2003 15:58:13
X-Message-Number: 24
I read with interest the posts on hidden transmitters. Here in MD the main
reason IMHO that packets don't get through is too much traffic. Here the
frequency saturation (UI-traffic)is typically 60-100%. Why? I'm sorry but
it seems to be mobile every 3 min, home stations at less than 1 hour, and
the party line use by truckers. Don't get me wrong all are realistic uses
of APRS but can't they be scaled back? I experience messages that time out
with no acks. The station was heard direct by mine but after 20+ tries I
cancleled. Went to another freq and we had solid contact @5W.
Also no smart digis and too much power from some in the area.
Example: watched Bob's mobile get picked up by digiA, within 1 min digiB
also retransmitted it. DigiA and B are almost line-of-site. As to power
some run 30+. Here in the east it doesn't seem to be needed...out west
maybe. Last thing traffic coming from an igate into RF, I don't digi it
but it's already "on-the-air"
I don't want to be a cop but for the system to be healthy we need to
educate without criticism. Thanks, "I've had mah say".. Buddy Ebsen
Jerry
N3SOK
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