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From: ZL3AI@ZL3VML.#80.NZL.OC
To  : APRDIG@WW

TAPR APRS Special Interest Group Digest for Saturday, July 03, 2004.

1. RE: Power, Path & Digis -- Part 2 of 2
2. Re: Power, Path & Digis
3. Re: Power, Path & Digis
4. New APRS digi for Windows (AGWUIdigi)
5. Re: APRS on a PDA?
6. Re: Power, Path & Digis
7. Re: Unproto Paths for Digipeaters
8. JFindu Down
9. Suffix for Ontario Canada
10. GPS to LCD project update

----------------------------------------------------------------------

Subject: RE: Power, Path & Digis -- Part 2 of 2
From: "WA8LMF@aol.com" <WA8LMF2@aol.com>
Date: Sat, 3 Jul 2004 20:21:05 -0700
X-Message-Number: 1

As a traveler outside of your home area, you may not know whether WIDE
or WIDEn-N digipeating is in use in a given area.  This is especially
true of simple trackers that transmit but don't receive -- you have no
way of monitoring what the locals are using.  Even if you do know, you
may not have the means (computer and configuration program) with you, to
reprogram your tracker to the correct path.

A good compromise path for travelers into "terra incognita" is RELAY,
WIDE, WIDE2-2.  In areas with dumb digis you will get two hops - dumb
digis will ignore the "callsign" WIDE2-2.   In areas with smart WIDEn-N
digis, you get up to 4 hops - smart digis WILL normally respond to the
non-SSID'ed "WIDE" as well as to WIDEn-N.

Some other considerations:

1) Normally, you would never put more than one "RELAY" in a path.

2) --NEVER-- put RELAY in a path after WIDE.  If you do this, dozens (or
hundreds) of home stations within earshot of one or more WIDEs will
needlessly clog the channel retransmitting the WIDE's packets for no
reason.

3) Paths longer than about WIDE4-4 are almost totally useless. The
probability of success goes down exponentially as the area covered by the
transmission expands outward, and the packet is exposed to more
possiblities of random collisions with users in distant areas.  On the
other hand, you can create literally thousands of useless packets for every
transmission, as the UI-FLOOD spreads outward over hundreds of miles.
Indeed, in some areas, intelligent digipeaters are automatically
reformatting excessivly long paths to something more reasonable such as
WIDE2-2 or WIDE3-3.

In a message dated 5/11/2003 8:26:55 PM Pacific Daylight Time,
jwsteven@concentric.net writes:

>I do have a question about gateways to HF and Internet.  I am guessing here,
>that now and then where ever access is available, one of the RELAYs or WIDE
>digis will also direct traffic to the Internet.

You've got it!  Typically Internet gateways ("Igates") are located at home
stations since an effective Igate has to have 24/7 Internet access (i.e.
cable, DSL, T1, etc ) which is hard to come by on top of a mountain or
water tower.  In other words, Igates are not typically co-located with
WIDES (unless they happen to be located in a tall building in a big city
where Internet connectivity WOULD be available) All the standard APRS apps
for Windows and Linux can perform the Igate function if desired.

>I haven't thought much
>about how APRS data enters and exits HF or the Internet for that matter.  Is
>the traffic logged on a server(s) somewhere and a request to findu retrieves
>it?

Exactly.  The APRS Internet System (aka APRServe) is a web of multiple
servers around the world cross-connected in two tiers that constantly
exchange heard data with each other.  In turn, hundreds (sometimes
thousands) of home stations around the world are logged into these servers
(the connections are standard Internet Telnet sessions). The local stations
feed packets heard off-the-air into the IS (and under some conditions
allowing Internet data to go back to RF).

In turn, Findu.com connects to some of these servers, captures and archives
everything the IS hears, and then does huge, fast database queries
everytime someone hits Findu with a request for a map.

It's not just Findu that can use the data flowing through the APRS IS. Any
standard WIndows or Linux APRS end-user program can connect to any of the
Internet servers in addition to (or instead of) your off-air
serial-port-interfaced TNC.  That is, you can install an APRS program on
your office computer, log into one of the APRS servers via your company
broadband connection, and play APRS with no radio at all!    The full,
unfiltered Internet feed representing heard stations all over the world is
a constant non-stop 15-20 KB/sec stream of data. You can not only track
mobiles but also send / receive APRS messages to / from mobiles "out
there". Many of the servers have "filter" ports that let you specify only
certain call prefixes, only within so many miles of a location, etc to
reduce the "firehose" of data to a more managable trickle, especially if
you aren't interested in tracking mobiles in Australia, Western Europe,
South Africa, etc

>I have a suspicion that long distance tracking can be rather spotty and
>that I might not show up for long stretches.

Again, you have correctly grasped the implications of the APRS
architecture.  Igates tend to be few and far between, outside of the larger
cities, and in the less populated and mountainous areas. The southwest WIDE
digipeaters in CA, NV, AZ and NM tend to be really really wide since they
are on 6000', 7000', 8000' or even higher mountain tops. The trick is to
bounce  the packet from your mobile through enough (but not too many)
digipeaters to finally reach an area where an Igate station is listening.

Normally really long-haul multihop digipeating is doomed to fail because
the probability of  packet collisions with local activity in the vicinity
of each WIDE.  The AZ-NM corridor is a rare exception because of the low
population density and correspondingly low level of local activity.

Once you leave the densely populated coastal regions or the southwestern
mountains, APRS coverage tends to be spotty islands around mid-sized or
larger towns with huge areas of nothing inbetween.    Of course the
Internet APRS server system acts as a "worm hole" that connects these
isolated areas.  In this respect, APRS behaves in a manner similar to
EchoLink, IRLP, etc.

>NM has an extensive
>mountaintop APRS system mostly on 144.39 now, I think.

144.390 is THE APRS frequency everywhere in the US and Canada.  In Europe,
the APRS action takes place on 144.800.

When you get REALLY out in the boondocks, an alternative is the HF APRS
system.  Virtually all HF APRS in North America is on 30 meters using 300
baud / 200 Hz shift HF packet format on 10.149.200 / 10.149.400 (actual
mark and space freqs).  This band is normally open for long-range
(500-to-2000 miles) transmission around the clock (and isn't plagued by the
massive shortwave broadcast interference that makes 40 meters unusable
after dark).

A few stations directly operate on this frequency but the frequency is
mostly populated by unattended Igates and Gateways that retransmit HF
activity to 2 meters where it can then find it's way to a 2 meter Igate.
   Normally on HF, you don't digipeat on frequency -- HF propagation is
too erratic.  The typical path is either:
     No path at all -  You hope to be heard directly by an HF igate station
or
     GATE, WIDE2-2
which tells the receiving HF station to retransmit you onto VHF.
[The majority of HF gateways are using Kantronics KAM TNCs which are
intrinsically capable of cross-gating the separate HF and VHF ports. ]

NEVER NEVER NEVER gate VHF activity the other way to HF!!!  HF operates
at a mere 300 baud. Even a single moderately active 1200 baud feed from
a two meter channel would monopolize the 30M frequency non-stop over
half the country!

Note that all this HF activity is on SSB which means your receiver has
to be tuned v-e-e-r-r-r-y precisely (typically within 10 Hz) and stay
there indefinitely.  Often you are shooting in the dark with no received
signals to tune in to verify the frequency.    Modern transceivers with
10-Hz resolution digital displays and (often optional) high-stability
master oscillators can do this,  but don't expect the vintage TS-820 or
FT-101 VFO rig to be even remotely usable for this application.

Note that the TinyTrak Ver 3.1 can do the 300 baud format required, but5
earlier versions can't. The commercially-built TigerTronics TigerTrak
also can do 30 baud HF but it lacks the TinyTrack's smart beaconing.  If
you run a laptop mobile, an alternative is a software TNC that uses the
sound card through a standard sound card interface (the same kind you
would use for RTTY, PSK31, etc) .  Both the AGW Packet Engine (freeware)
and MixW ($60 registerware) can act as HF 300 baud TNCs entirely in
software.

Stephen H. Smith                   wa8lmf (at)  aol.com
Home Page:                            http://wa8lmf.com

----------------------------------------------------------------------

Subject: Re: Power, Path & Digis
From: "John Langtry, VE3NEC" <ve3nec@sympatico.ca>
Date: Sat, 03 Jul 2004 00:24:20 -0400
X-Message-Number: 2

Gretings Peter,

I agree, there are lot's of "drum head" lawyers out there, who have endless
complaints, and really little to offer, espcially for the new chap on the
block.

If your local digi supports the WIDEN-N, then your current path of WIDE 3-3
works. In fact we have seen you from time to time up here (near Toronto,
Ontario).

However, a suggestion. If you're planning a holiday vacation, to change
your paths (both Posit and Beacon) to "RELAY, WIDE2-2", if you don't know,
the machines' abilities, you can use a path of "RELAY, WIDE,WIDE" and have
done with it.

This way, when you're mobile, any station on frequency will give you a
"boost" into the Network, if they can hear your transmissions.

Yes, there will be duplicates in sub-urban areas, and there will be many
who will (potentially) complain.

The trick here is in the timing of each report.

Your Status Beacon, should go out every 9 minutes while mobile in the U.S.
(to meet FCC rules), if you come to Canada for your vacation, every 29
minutes fits our (DOC) rules.

On the other hand, your position (Posit) should be sent every 3 ~ 5
minutes, if you've got a V-8 and a lead foot ! (Guilty, as charged), still,
if your stopped for food & fuel, you could drop this to a Posit every 20
minutes or so, just to keep our maps alive.

I don't know the area that you plan to take, machines and their abilities,
nor how congested the network is in the areas - so all of the above are
just "general" guidelines.

With no doubt, the Sea-Lawyers will have more to say (that's that they made
the <delete> key for) on your topic.

Me ? I'm no "expert" but I am an experimenter, try something, and tweak
something. But I did "tweedle" out my first packet frame (SDLC) on June 16,
1979. I've never looked back since then ! ("Come along with me, The best is
yet to be !")

Which makes you wonder, where were the "lawyers" back then ?

vy 73 de John VE3NEC
905-873-8715

----------------------------------------------------------------------

Subject: Re: Power, Path & Digis
From: "Ron Cluster" <rcluster@rgisp.com>
Date: Fri, 2 Jul 2004 22:47:24 -0700
X-Message-Number: 3

John wrote:

The trick here is in the timing of each report.

<snip>

Actually the trick is using a proper path......

WIDE 3-3              will not work,

RELAY, WIDE,WIDE      will not work,

RELAY, WIDE2-2        also will not work

However....

WIDE3-3 or RELAY,WIDE,WIDE or RELAY,WIDE2-2 will both work just fine (No
spaces in the path). Nitpickin' I know, but it doesn't help a beginner to
give out misleading info. To further complicate matters, there are areas of
the US (Los Angeles metro area comes to mind) where the system has been
intentionally broken by disabling RELAY. So in those areas, neither of the
above paths will work. It's best to check around and see what others in your
area are doing.

73.....Ron.....AC7TK.....(-9 when mobile)
UI-View32 iGate in Eugene, OR

----------------------------------------------------------------------

Subject: New APRS digi for Windows (AGWUIdigi)
From: "\(SV2AGW\)George Rossopoulos" <sv2agw@raag.org>
Date: Sat, 3 Jul 2004 11:36:45 +0300
X-Message-Number: 4

Hi

AGW UI Digi. An APRS digi.

Supports WIDEN-N, TRACEN-N
Cross band digi.
Unlimited "Alias" 
Unlimited digipeating rules
Unlimited cross band rules

And as usual easy setup for everyone, no need to have an APRS Master to use
it.
Default settings allow RELAY only digepeating.

www.elcom.gr/sv2agw

73

(SV2AGW)George Rossopoulos
sv2agw@elcom.gr
www.elcom.gr/sv2agw
+306932465216
George Rossopoulos
Nikanoros 59
54250,Thessaloniki
Greece

----------------------------------------------------------------------

Subject: Re: APRS on a PDA?
From: John Vause <jdv@iglou.com>
Date: Sat, 03 Jul 2004 08:13:07 -0400
X-Message-Number: 5

Curt, WE7U wrote:
>On Mon, 28 Jun 2004, Jason Winningham wrote:
> 
>>On Jun 28, 2004, at 12:16 PM, WA8LMF@aol.com wrote:
>>
>>>1)  PDAs are NOT shrunken PCs.  

Well, my Zaurus 5600 PDA has just about replaced my laptop for network 
diagnosis and 802.11b security analysis.
And it still acts as a PIM, word processor, runs spreadsheets, databases,
etc.
It runs Linux programs that have been compiled for the ARM or XScale
processors.

>There's also the Sharp Zaurus models, which come with Linux on them
>exclusively (I think with the Qt widget, not full-blown X11
>underneath).

Unfortunately, X11 is too big for the internal storage on the Zaurus. It
can be made to work (I haven't done it) by reflashing the Zaurus with the
X11 rom and moving most of the X11 binaries to CF or SD cards.

>Nobody has tried Xastir on a PDA to my knowledge.  The main Xastir
>screen can be shrunk down awfully small, but it's not intended to be
>run on that size of screen currently.  All of the configuration and
>mouse dialogs would be too large to deal with, unless you configured
>the device with a large virtual screen and could pan around.

Roadmap displays fairly well on my 5600 and it uses TIGER map data.
Now if it only had APRS support.

How about a port of Bob's APRSDOS?

>Anyone wanting to donate a Zaurus to the cause, you have MY e-mail
>contact info!

Sorry Curt, I'm much too fond of mine to let it go. :-)

-- 
* John Vause  KF4ERV  jdv@igloudot.com                *
* NOTE: email address altered for benefit of Spambots *
* My favorite law: The Law of Unintended Consequences *
*                              -- John Vause          *
--

----------------------------------------------------------------------

Subject: Re: Power, Path & Digis
From: Phil Reed <preed@dnaco.net>
Date: Sat, 03 Jul 2004 08:28:07 -0400
X-Message-Number: 6

At 12:24 AM 07/03/2004, John Langtry, VE3NEC wrote:
>Your Status Beacon, should go out every 9 minutes while
>mobile in the U.S. (to meet FCC rules), if you come to
>Canada for your vacation, every 29 minutes fits our (DOC)
>rules.

Actually, as long as you use your call sign in the MYCALL setting (as 
opposed to a tactical call sign), every packet is already properly 
identified. The additional status packet is nice, but redundant.


>On the other hand, your position (Posit) should be sent
>every 3 ~ 5 minutes, if you've got a V-8 and a lead foot !

This depends to a certain extent on what you're trying to accomplish. There 
is reasonable justification for mobile stations to transmit every minute 
while moving.

>Me ? I'm no "expert" but I am an experimenter, try something,
>and tweak something. But I did "tweedle" out my first packet
>frame (SDLC) on June 16, 1979. I've never looked back since
>then ! ("Come along with me, The best is yet to be !")
>
>Which makes you wonder, where were the "lawyers" back then ?

Oh, they were around. They just hadn't discovered data transmissions at 
that point.

--
                                  ...phil / w8sca

"For a list of all the ways technology has failed
     to improve the quality of life, press 3."

----------------------------------------------------------------------

Subject: Re: Unproto Paths for Digipeaters
From: Earl Needham <needhame1@plateautel.net>
Date: Sat, 03 Jul 2004 10:03:41 -0700
X-Message-Number: 7

At 06:58 AM 6/29/2004, Dennis Hudson, N2LBT wrote:
>Which is it then Earl? You constantly advocate the need to run WIDE7-7 in 
>your area,

No, I don't.  You won't find me advocating a 7-hop path anywhere.  What I
DID say was that digis should run a path with more than one hop here.  I'd
suggest you read a little closer before throwing accusations my way.

> (even though people complain in cities along the gulf coast).

Uh -- there's no path that I know of from here to the Gulf Coast.  The
network just isn't there.

> The point being, if you are using WIDE7-7 and not direct paths why do
>you need to know what digis are out there?

As I said in my first post, I like to see them, that's all.

7 3
Earl

Earl Needham, KD5XB, Clovis, New Mexico  DM84jk
SETI@Home:  11637WU/7.55yrs

----------------------------------------------------------------------

Subject: JFindu Down
From: "AE5PL Lists" <HamLists@ametx.com>
Date: Sat, 3 Jul 2004 14:38:24 -0500
X-Message-Number: 8

www.jfindu.net was down from 0330Z to 1915Z due to the server being
relocated.  It is up and running, however no data collection was done
during that time.  Sorry for the inconvenience.

73,

Pete Loveall AE5PL
mailto:pete@ae5pl.net

----------------------------------------------------------------------

Subject: Suffix for Ontario Canada
From: "Bill Bird" <kg0yj@arrl.net>
Date: Sat, 3 Jul 2004 20:51:38
X-Message-Number: 9

As I drive around Ontario Canada will it suffix to use KG0YJ/3 for APRS 
use?

73,

Bill
KG0YJ

----------------------------------------------------------------------

Subject: GPS to LCD project update
From: "Andrew Rich" <vk4tec@hotmail.com>
Date: Sun, 4 Jul 2004 13:37:56 +1000
X-Message-Number: 10

Howdy,

I have added some more screens to my GPS to LCD project.

1. POS(ition) Lat / Lon
2. DTG (Date and Time)
3. SAT(ellites) fix, no of sats in view
4. VEL(ocity) Speed and direction

http://www.tech-software.net/16f628.htm

Chees Andrew 

---

END OF DIGEST



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