[OZAPRS] VHF and HF APRS

Mike Zwingl oe3mzc oe3mzc at oevsv.at
Wed Dec 3 22:20:40 EST 2008


Ian,
congrats.
I made a similar trip in WA and Africa with Hf-APRS.

Here are my findings:
always only use ONE SSID, in order to produce one single track, made out of 
different sources. (HF, VHF or ISS)
I would use SSID-9 for all.
Use the 4WD symbol.
Use a Opentracker OT1plus for VHF/ISS, with speed, Temperature and sealevel 
enabled. (cheaper and more flexible than TinyTrack TT3 or TT4)
Use Smartbeaconing to have flexibel intervall.
Use COMPRESSED format to save transmision time. (Base91 compressed) keep 
posit short!
Do NOT use COMMENTS in each packet. Use "SEND EVERY 5th packet " -function 
for sending additional information.

Install a switch on OpenTracker1plus to switch profiles between HF/VHF 
(300Baud/1200Baud)

It is worth to use the "Power Relay" option of your tracker. This will 
switch off the TRX and GPS to save battery power in the outback, while you 
are on camp and Tracker will only switch on peripherials just before a posit 
transmission.

For Shortwave it would be even better to use a DSP-TNC Tracker from SCS. It 
can be used standalone APRS Tracker or as a kiss-tnc for emails. Its always 
a good idea to have a tracker in spare on such a trip anyway.

Use only 50 W and good / short cabeling from the 12Volt battery, otherwise 
ur signal will be distorted easily.

Bay the way: try ISS. If transponder and SATgate is functional, it is worth 
the try. But as the operation window is very short, use profile with shorter 
intervall. (only few users in OZ)

Have a save trip!
vy 73 de Mike
oe3mzc
ex/VK3FPF




----- Original Message ----- 
From: "Ian Bennett" <ibennett at tpg.com.au>
To: "Australian APRS Users" <ozaprs at aprs.net.au>
Sent: Tuesday, November 25, 2008 2:06 AM
Subject: Re: [OZAPRS] VHF and HF APRS


> Group,
> I had read this however I was seeking some additional guidance. Probably 
> best
> if I work a scenario.
> I have VK1IB-9 entered into my VHF tracker and VK1IB-15 in my HF one. I 
> start
> on my trip.
> Those watching my progress will see two separate icons in the same place.
> Ugly, but no problem for the moment.
> As I progress, I eventually get out of range of any VHF repeaters. VK1IB-9
> stops. HF is still operational so VK1IB-15 continues to move. Now anyone
> watching my progress sees two icons in different locations. This outcome 
> is
> not what I am looking for.
> I want people tracking my progress to see one icon only, updated with
> position reports from the "best" source.
> From what I am reading, I should be leaving my VHF APRS gear at home 
> right??
>
> Ian
>
>
> On Tue, 25 Nov 2008 11:48:39 Phillip wrote:
>> Hi Ian
>>               Congratulations and welcome to Amatuer radio
>>
>> To answer your questions there are standard SSIDs for most applications
>>
>> attached is the standard SSID recommendations
>>
>> 73 Phillip
>> ZL2TZE
>>
>> APRS SSID Guide
>>
>>
>>
>> Since there are many APRS users on the air, the APRS maps and data can
>> get very cluttered.  Also, most operators have multiple stations on the
>> air, such as their HOME, CAR, BOAT, and HT.  It is very convenient to be
>> able to recognize these typical applications at a glance.
>>
>>   Here are those common defaults:
>>
>>
>> -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)
>> -6 is for Operations via Satellite
>>
>> -7 Kenwood D7 HH
>> -8 is for boats, sailboats and ships (maybe 802.11 in the future)
>> -9 is for Mobiles
>> -10 is for operation via The internet only
>> -11 is for APRStouch-tone users  (and the occasional Balloons)
>> -12 Portable Units such as Laptops, Camp Sites etc.
>> -13 Un-asigned
>> -14 is for Truckers
>> -15 is for HF
>>
>>
>>
>> Originally, in 1992, the first APRS GPS mobiles just transmitted raw
>> NMEA-0183 GPS stings and so there was no way to insert a SYMBOL byte in
>> the pre-formatted NMEA 183 packet.  Hence we defined 14 common SYMBOLs as
>> defaults to the 14 available SSID's that a mobile could use.  These
>> included BIKES, HELICOPTERS, AIRCRAFT, VANS and many others in addition
>> to the ones above.  This is now OBSOLETE.
>>
>> In the late 1990's we came up with a better solution and defined the
>> AX.25 TOCALL of GPSxyz for such use.  In this case, the "xyz" characters
>> can be used to define any of the hundreds of APRS symbols including
>> Overlays.   Just look up the xyz in the SYMBOLS.TXT file included in all
>> copies of APRSdos (or these days, on the WEB).
>>
>> Since this GPSxyz concept was so powerful, it completely replaced the
>> original SSID assignments and so those original NMEA defaults have been
>> removed from the Documentation.
>>
>> However the convention for the 6 most useful ones remains and should be
>> used in the absesnce of any other overriding conditions.  Except for the
>> TH-D7 and Truckers, the other SSID conventions mark APRS "TYPES" of users
>> that are independent of the many SYMBOLS they can use.  Thus it is nice
>> to know HOW someone is getting into the system, whether via satellite,
>> HF, the internet, or touchtone.  For example, using the -6 only for Space
>> applications is so that the global APRS WEB data bases will keep
>> statistics and data for when you are operating through the satellites
>> separate from when you are working normally.
>>
>> So stick to the standards above for the obvious applications...  Of 
>> course
>> these are not rigid.  If you have more than 4 digipeaters, use any SSID
>> you want.
>> These are only guidelines...
>>
>> de WB4APR, Bob
>
>
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