Welcome to the VK8 APRS information page

The purpose of this page is to provide amateurs in the Darwin area and others visiting with information and guidelines to help setup an effective and useful APRS station.

A basic understanding of amateur packet operations is assumed. It is not the aim of this page to help you get your radio connected to a TNC and working properly.


NOTE: The IGATE and Digi are now located in Darwin's Northern Suburbs

From July 2005 Stuart VK8NSB has taken over the hosting of APRS in Darwin. He has a better site then the old Larrakeyah site!! The server software is still the same but running on a faster PC. Stuie and I looking to add DX cluster and other services to the system so keep an eye on this page for updates.

Simon VK8JZ



What is APRS?

APRS is short for Automatic Position Reporting System, which was designed and is copyright to Bob Bruninga, WB4APR, and introduced by him at the 1992 TAPR/ ARRL Digital Communications Conference.

Fundamentally, APRS is a packet communications protocol for disseminating live data to everyone on a network in real time. Its most visual feature is the combination of packet radio with the Global Positioning System (GPS) satellite network, enabling radio amateurs to automatically display the positions of radio stations and other objects on maps on a PC.
Other features not directly related to position reporting are supported, such as weather station reporting, direction finding and messaging. APRS is different from regular packet in several ways:

Conventional packet radio is really only useful for passing bulk message traffic from point to point, and has traditionally been difficult to apply to real-time events where information has a very short lifetime. APRS turns packet radio into a real-time tactical communications and display system for emergencies and public service applications.APRS provides universal connectivity to all stations, but avoids the complexity, time delays and limitations of a connected network. It permits any number of stations to exchange data just like voice users would on a voice net. Any station that has information to contribute simply sends it, and all stations receive it and log it. APRS recognizes that one of the greatest real-time needs at any special event or emergency is the tracking of key assets. Where is the marathon leader? Where are the emergency vehicles? What's the weather at various points in the county? Where are the power lines down? Where is the head of the parade? Where is the mobile ATV camera? Where is the storm? To address these questions, APRS provides a fully featured automatic vehicle location and status reporting system. It can be used over any two-way radio system including amateur radio, marine band, and cellular phone. There is even an international live APRS tracking network on the Internet.

APRS Features

APRS runs on most platforms, including DOS, Windows 3.x, Windows 95/98, MacOS, Linux and Palm. Most implementations on these platforms support the main features of APRS:

APRS® is a registered trademark of Bob Bruninga.
WinAPRS, MacAPRS, X-APRS, PalmAPRS and APRS/CE
are trademarks using the APRS® name, licensed from Bob Bruninga.

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Whats on APRS in the Northern Territory?

Darwin area

The national APRS frequency of 145.175 Mhz has been adopted and the BBS user frequencies have been left BBS users. Below is a summary of the main network building blocks with a description of the functionality and coverage of each. Generic RELAY WIDE and WIDEn-n TRACEn-n are all supported in this network. See APRS spec 1.0.1 for more info.

VK8NSB-5 I-gate- Leanyer

This is not actually a digipeater but is an IGATE. Through the Igate in Darwin we can see many other stations on a Australia wide. The Igate carries position frames as well as message,objects type frames onto and off of the internet. VK8NSB-5 is running a UI-View 32 on Windows 98 listening on 145.175 Mhz. The VK8NSB-5 I-gate is located north of the Darwin CBD. It serves the Darwin CBD and surrounding suburbs. The gate has an output of 5 Watts into a 1/2 Wave vertical antenna.

VK8NSB-1 Digi- Leanyer

VK8NSB-1 digipeater is co-located with the igate approximately 12km north of the CBD. It is running the digi_ned intelligent APRS digipeater software. This provides some additional features over the UIDIGI firmware. Functions like the Tiny Web Pages, Satellite Tracking, Announcement of APRS DX (stations heard direct over a preset distance) are available.WIDEn-n TRACEn-n RELAY and WIDE digipeating are supported as well as Via its own callsign. VK8NSB-1 will respond to PING, QUERY and QUERY ALL STATIONS. Extended command features available via APRS messaging are listed below. Just send a message to VK8NSB-1 Via your required path.

These commands are sent as messages to VK8NSB-1.

?help - shows a short overview of all commands
?id - shows the own call and the call of the DIGI_NED owner
?ver - shows version and date and time of compilation
?up - shows date and time of the last restart
?type - shows that this is DIGI_NED
?ports - shows the number of available ports
?aprsd - shows directly heard station, maximal 5, no ack
?mheard - shows help for the mheard command
?mheard 1 - shows heard stations on port 1
?mheard pe1dnn - shows when pe1dnn was last heard, with port number
?mh - just like mheard, only shorter
?dx - shows help for the dx command
?dx 1 - shows best dx on port 1, all history, last 24h and last hour
?dx pe1dnn - shows distance and bearing to pe1dnn
?ping? - shows the path of the requester to the digipeater, no ack
?aprsm - retransmits all unacknowledged messages for the requester
?aprst - same as ?ping?
?wx - beacons weather report imediate
sats - returns supported satellites
sat list - returns supported satellites
sat ao40 - returns if satellite (ao40) is in range, position and AOS
trk ao40 - tracks ao40. beacons every 15 mins until in range then every 1 minute until out of range.


APRS telemetry will be tested in the future.

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How Should I setup my APRS Station?

Here is a guide as to how to setup your station within the Adelaide network which allready extends into rural areas. This section is divided into 2 distinct parts, home setups and mobile setups. There are fundamental differences in these 2 different situations. This guide is based roughly around the setup of the UI-View program as that seems to be the more popular currently. It does still however in principal apply to other programs in use. So if you running another APRS software package read on anyway.

Please be aware that YOU can have a direct influence on the health and effectivness of the network. Bad settings on your behalf will cause a degredation of the network functionality. This can easily cause many unnecessary frames on air thus causing unnecessary wear and tear on your radio and power bill and at the same time spoil the fun for everyone else. Please try to absorb and apply these principals and we will all co-habit nicely on APRS. Its not my intention to make a set of rules that must be followed. I am not a packet policeman. Its up to you. These are my thoughts and findings and others may not agree completely but we do need a starting point for setting up our APRS stations.

Home Station Setups.

This section is divided into 2 distinct parts. Transmission of Your frames and Your Digipeater.

Lets look at Your own transmissions:

Recomended path is VIA WIDE in UI-View this is set in Menu Setup/Station Setup. The Unproto address box this would read as APRS,WIDE. Dont use a path with RELAY in it like APRS,RELAY,WIDE unless you are not in reliable range of a high sited WIDE digi. For the vast majority of us at home this is not a problem to achieve.

If you want to run with a compressed beacon then go right ahead. Most systems these days including the latest APRS-DOS can understand this with no problems. It will increase the likelyhood that your frames get through by decreasing the frame size and cutting back on channel traffic.

Timing. Recomended timing for beacons of fixed stations is 30 mins. In UI-View this is set in Menu Setup/Station Setup where the Fixed beacon interval box should read 30 . We run a net turnover time of 1 Hour so set your expire time to 60 mins. Also object intervals should be 20 mins or greater. In UI-View both these time settings are found in Menu Setup/Miscellaneous.

Callsign SSID. It seems sensible for home stations to run with SSID 0 where possible as a convention. For messaging in particular it can cause less confusion. In UI-View this is set in Menu Setup/Station Setup in the callsign box where you can enter your own callsign with no SSID Eg. VK8XYZ . See the listed SSID conventions below which are allready in heavy use around VK.

VK guide for APRS SSID use. thanks to Bob WB4APR and Richard VK3JFK

-0 Home Station, Home Station running IGate.
-1 Digipeater, Home Station running a Relay Digi, Wx Digipeater
-2 Digipeater [#2 or] on 70CM
-3 Digipeater [#3]
-4 HF to VHF Gateway
-5 IGate (Not home station)
-7 Kenwood D7 HH
-9 Mobiles
-12 Portable Units such as Laptops etc.

Another one that I use frequenctly is -6 for "special" things like stations using the Satellites. This is so that those stations show up separately on FINDU and other systems instead of being overwritten as soon as someone QSY's back to the Terrestrial system.
Also for those that have both a D7 (-7) and a mobile (-9) but also have a D700 in the other car, I use -8...

Lets look at Your Digipeater:

This is where many of us come unstuck. Just enabling everything that you can is the worst possible thing you can do. If your running from home and your in range of a WIDE digi on the hill somewhere then DONT run with WIDEn-n or TRACEn-n enabled. If you want to help the network then you can set yourself up as a RELAY . This will assist mobiles running with trackers and the like. Running as a RELAY requires a bit of decernment however. If there is allready a station nearby that runs often or continually and is allready running as a RELAY then your not helping anybody by setting it up yourself. Now refering directly to UI-View this is found in Menu Setup/Digipeater setup. In here you can Enable digi and also Enable Alias substitution. In the Alias(es) box insert both your callsign and RELAY with a comma to seperate them. This would read as VK8XYZ,RELAY . In the Sub Alias box you need to insert your callsign VK8XYZ .

So in a Nutshell for Home stations:

UNproto Path Via WIDE3-3, Beacon every 30Mins compressed if possible, Only run RELAY as a Digipeater Alias if you run Digi at all and if possible enable callsign substitution. If you generate OBJECTS then time them at 30 Mins.

Mobile Station Setups.

Most mobile setups in Adelaide are based on the Tiny Track and similar devices at this time. That doesnt however mean that you wouldn't run a TNC in a mobile.

Lets look at Your own transmissions:

Recomended path is VIA RELAY,WIDE or something of similar structure. Note the use of RELAY before WIDE. This makes use of available home stations that will act as a first Hop when they are available. If they are not available then the high sited fixed Digis (VK8NSB-1) will become the RELAY part of the path. Never use RELAY,WIDE,RELAY or something with RELAY as the last hop. You will saturate the network needlessly. All the full time Digis in use on the hills support Flood WIDE operation so use WIDE3-3 instead of WIDE,WIDE,WIDE .

Timing. As a general rule mobiles should only beacon once every 60 Seconds when mobile. Some Tiny Trackers have a facility for smart beaconing on corners etc which will tend to defeat this at times. However if you send out beacons at a greater rate than each 60 seconds on a regular basis (ie. once each 30 seconds) then they will likely be ignored or just missed due to the fact that you have saturated the network. Dont forget there are likely other mobiles out there as well. If you can run compressed frame encoding then do so as it really cuts down the frame size greatly increasing your chances of making it into the network and leaving more channel bandwidth for others to use. If you have a switch for alternate timing when your car is parked then set this timing for 10 minute intervals. Some TNC's and Tiny Tracks can sense the vehicals motion and increase the frame intervals automatically when stationary. There are some easy tricks you can do with the battery voltage or ignition wiring to make this switch over on earlier Tiny Trackers and similar setups. Switching your timing when the vehical is parked has multiple advantages for you and others and is very much recomended.

Callsign SSID. Try to make sure you run as per the guide below in your mobile . With TNC based mobile systems running with a GPS sending raw NMEA strings often the SSID is used to establish the Vehical symbol but these are not very common these days. Read the APRS spec for more info. If we all start to follow these conventions then we have a fair chance of working out what each other is running and the associated capabilities it has.

VK guide for APRS SSID use. thanks to Bob WB4APR and Richard VK3JFK

-0 Home Station, Home Station running IGate.
-1 Digipeater, Home Station running a Relay Digi, Wx Digipeater
-2 Digipeater [#2 or] on 70CM
-3 Digipeater [#3]
-4 HF to VHF Gateway
-5 IGate (Not home station)
-7 Kenwood D7 HH
-9 Mobiles
-12 Portable Units such as Laptops etc.

Another one that I use frequenctly is -6 for "special" things like stations using the Satellites. This is so that those stations show up separately on FINDU and other systems instead of being overwritten as soon as someone QSY's back to the Terrestrial system.
Also for those that have both a D7 (-7) and a mobile (-9) but also have a D700 in the other car, I use -8...

Digipeaters. I have never seen a need to run a mobile Digi. Dont run a digi of any sort from your mobile. Imagine the mess it makes when a messaging path is established between 2 stations and then half way through the chat/messaging the established path stops working. Ive seen it happen because a mobile station was running an alias of RELAY. This is only possible if you take your TNC mobile as a Tiny Track wont run as a Digi. If you take your laptop mobile with the GPS etc then make sure you disable the Digi. Refering directly to UI-View this is found in Menu Setup/Digipeater setup.The only situation I could see you would run a digi in the mobile is perhaps in a temporary portable situation like a Camp or WICEN exercise. This would perhaps be helpful if you ran with a RELAY alias with some discretion.

So in a Nutshell for Mobile stations:

UNproto Path Via RELAY,WIDE, Beacon every 60 seconds when mobile and 10 mins when parked, Dont run a Digi Alias if you have a TNC based system in your mobile.

Here are some other timing parameters of interest as well:

1 minute for mobiles 3-6 on frequency at once
2 minutes for mobiles >6 on frequency at once
10 minutes for mobiles that are stationary
10 minutes for weather stations
30 minutes for home stations
30 minutes for Objects
20 minutes for Digipeters

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What if I don't have APRS Software?

Manually setting your location information.

If you are not using any APRS software, but you would still like to send your position it is possible.   All you need to do is to set your TNC's Beacon Text (BTEXT) to include one of the beacon strings below.  

Gridsquare method:

To beacon your location as a gridsquare, you must set your BTEXT to something like the following:

[QF54RD] This is my beacon etc…..

All the APRS system looks at is the info inside the square brackets at the start of your beacon. Your station will be plotted randomly somewhere inside the square you nominate, and the GRIDSQUARE symbol will be used for the map icon.

Co-ordinates method

Your BTEXT contains the latitude and longitude of your station. Obviously this is more accurate, but if giving away your EXACT location is a concern you can round off the seconds or minutes to offset your true position. This method also allows you to choose which symbol will be shown on the maps of those watching. To use this method, set your BTEXT to be similar to:

!3344.78S/15028.92E- this is my beacon etc etc….
| | | | ||  | |  |||
| | | | ||  | |  ||+- Symbol to use on the map display (In this case a House)
| | | | ||  | |  |+-- East
| | | | ||  | |  +--- Seconds in decimal (seconds/60)
| | | | ||  | +------ Minutes
| | | | ||  +-------- Degrees
| | | | |+----------- Symbol table to use (/=Standard, \=Alternate)
| | | | +------------ South
| | | +-------------- Seconds in decimal (seconds/60)
| | +---------------- Minutes
| +------------------ Degrees
+-------------------- Indicates an APRS position beacon

SYMBOL

STANDARD  /

ALTERNATE   \

Police Station

Emergency

"

   

#

Digipeater

Numbered Digipeater

$

Telephone

Bank

%

DX Cluster

 

&

HF Gateway

Numbered Diamond

'

Small Plane

Crash Site

(

Cloudy

Cloudy

)

   

*

 

Snow

+

Red Cross

Church

,

Boy Scout

Girl Scout

-

Home

Home with HF

.

X

 

/

Dot

 

0

Circle (0)

Numbered Circle

1

Circle (1)

 

2

Circle (2)

 

3

Circle (3)

 

4

Circle (4)

 

5

Circle (5)

 

6

Circle (6)

 

7

Circle (7)

 

8

Circle (8)

 

9

Circle (9)

Petrol Station

:

Fire

Hail

;

Campground

Park

<

Motercycle

Numbered Car

=

Train

 

?

Car

Information Booth

@

File Server

Hurricane

A

Aid Station

Numbered Box

B

BBS

Blowing Snow

C

Canoe

Coast Guard

D

 

Drizzle

E

Eyeball

Smoke

F

 

Freezing Rain

G

Gridsquare

Snow Shower

H

Hotel

Haze

I

TCP/IP Gateway

Rain Shower

J

 

Lightning

K

School

Kenwood

L

 

Lighthouse

M

MacAPRS

 

N

NTS Station

Nav Buoy

O

Balloon

 

P

Police

Parking

Q

 

Earthquake

R

Recreational Vehicle

Restauant

S

Space Shuttle

Satellite

T

SSTV

Thunderstorm

U

Bus

Sunny

V

ATV

VOR

W

Wx Service

Numbered Wx Service

X

Helicopter

Pharmacy

Y

Yacht

 

Z

WinAPRS

 

[

Jogger

Wall Cloud

\

Triangle

 

]

PBBS

 

^

Large Plane

Numbered Plane

_

Wx Station

Numbered Wx Station

`

Satellite Dish

Rain

a

Ambulance

RSGB, ARRL

b

Bike

Blowing Dust

c

 

Numbered Civil Defence

d

Double Garage

DX Spot

e

Horse

Sleet

f

Fire Truck

Funnel Cloud

g

Glider

Gale

h

Hospital

Ham Store

i

IOTA

 

j

Jeep

Work Zone

k

Truck

 

l

 

Area Location

m

Repeater

Milepost

n

Node

Numbered Triangle

o

EOC

Small Circle

p

Rover

Partly Cloudy

q

Gridsquare

 

r

Antenna

Restrooms

s

Power Boat

Numbered Boat

t

Truck Stop

Tornado

u

18 Wheel Truck

Numbered Truck

v

Van

Numbered Van

w

Water Station

Flooding

x

XAPRS

 

y

Yagi

 

z

 

 

{

 

Fog

|

 

 

}

 

 

~

 

 

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Useful APRS LINKS

Darwin Amateur Radio Club

Darwin IRLP Node (6800)

G4IDE's Ui-view Home page

Ui-view Web resource

TAPR APRS Special interest group page

Bob Bruninga WB4APR APRS Page

Byonics Tiny Trak Pages

Findu.com APRS station finder

Pcsat Webpage

ARISS-FAQ

 

Australian Links

APRS in VK

APRS in VK2

APRS in VK3

Darryl Smith VK2TDS GPS/APRS Page

VKAPRS Server status report

Adelaide/VK5 and Australian APRS Maps - Live Traffic as seen via the Igate

Want to connect a WM918 Weather station to any TNC or even a Ui-Digi? Check out this from VK5EX.

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Last updated 20 August, 2005