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[aprssig] RE: Message wild card

Robert Bruninga bruninga at usna.edu
Wed Aug 1 14:14:05 UTC 2007


>> You wrote,"  Simply set a wild-card (*) 
>> in your MSG GROUP on your D7 or D700, and then 
>> your radio will receive and display ALL 
>> message traffic....
>  
> The D700 comes set to "Unprotocol APK101"  
> (setting APRS 3-E) which I have left. 
> Is there a difference in message reception 
> between this and inserting the (*) in the 
> MSG GROUP field?

Yes, apples and oranges.  The MSG group has to do with the
receipt of APRS message traffic.  Normally you only receive
messages addressed to your own callsign, and to the default
message groups of ALL, QST, CQ and KWD.  You can define any
other message groups.

For example we put USNA into the message group list of all Naval
Academy Kenwoods so that we can sent a groupp message to USNA
and all of the participants in our annual football tracking run
will get the message.

See http://www.ew.usna.edu/~bruninga/fball2006.html

The UNPROTO field on the kenwood is "misslabeled" in my opinion.
It should be labeled "ALTNET" which is defined in the APRS spec
as the ability to set up a subnet on the APRS network so that
stations operating with the same ALTNET will see and track only
each other and will not see or be seen by other systems on the
APRS channel.  But there are several caveats:

1) This assumes that client softare honors the ALTNET concept.
(many do not. They will capture and display everything, no
matter what the ALTNET.

2) By definition, all Mic-E (Kenwoods) can not distinguish an
ALTNET on transmit, therefore, even systems running under an
ALTNET will receive and display the positions of all other
MIC-E's (kenwoods) whether they are participants or not.

3) When not used as an ALTENET, that menu item in the kenwood is
used to indicate the firmware version of your APRSradio.  It is
not a good idea to change that, unelss you write it down and can
restore it later.

So, in most cases, never change your UNPROTO setting.
But you can use a * in the MSG GROUP list to monitor other
message traffic.

Hope that helps
Bob, Wb4APR






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