Wednesday, April 29, 2015

3000 baud and nothing wrong!

Most VHF/UHF rigs have "9600 baud" capable ports built into them.  Without going into a long-winded explanation, the port bypasses the pre-emphasis circuitry of the radio so that 9600 bps operation is possible.  Plus, you have to get a 9600 baud TNC, like the Kantronics KPC9612.  Looking at a few hundred dollars for that.

So, most of us have grown accustomed to "1200 baud" only on non-9600 baud radios.

Scott KD5NJR and I have experimented with the new "8PSK" modes that were added last fall to the FLDIGI suite of programs.  Running 8PSK-1000 is the equivalent to running 3000 baud.  Yes, two and a half TIMES faster than a standard TNC.  I was sent him a 77K file in less than 5 minutes.

I encourage everyone to try out the super-speedy 8PSK modes on VHF/UHF, especially considering you will have no added cost outside of your soundcard interface to the radio.

Sunday, April 26, 2015

Wednesday, April 15, 2015

For the next APRS net...

On this past "statewide" APRS net, I had some APRS OBJECTS that marked my station as the net control station.  I also had a couple similar OBJECTS that had in the comments field instructions to message me to check in, or to find me on a talk-in channel, etc.

Jeff has a good idea to do the same thing with APRS BULLETINS.  I think that worked even better.  I'd not tried bulletins because I was unsure how to name them.  But it's not hard. 

But here is what I want to do next time.

NCS first sends a message to ANSRVR with the contents CQ OKAPRS Let's Start the Net

Optional : A message to ANSRVR containing D OKAPRS stateside net at 1300 CDT ... or something to provide a bit of a description.

Participating stations join the net by sending a message to ANSRVR with the contents J OKAPRS

Participating stations send a message to Net Control (and everyone else, like a conference call ) with a message to ANSRVR , again with the contents of CQ APRS xx5xxx checking in ... or other traffic.

And when we're done, people can log out of the net with a U OKAPRS message sent to ANSRVR.

The NCS can check on the number of participants with a ? OKAPRS message.

Jeff pointed this out in a deck of slides he provided to Lloyd recently.

Scott / KD5NJR

Monday, April 13, 2015

May 2015 QST : APRS

Guys, I didn't read it yet myself, but Lloyd asked I mention the May 2015 QST as a source of information about APRS.  I have to admit, I didn't read it yet myself.


Naming your APRS Station

... some guidance on naming your APRS station ...
... again, more food for thought.

APRS SSID Recommendations                                  6 Feb 2012

Updated 6 Feb  2012 to clarify the title of this document to be
                    SSID RECOMMENDATIONS not to imply any kind of 
                    decoding "standard".  That original NMEA
                    decodign standard is covered in the original spec
Updated 9 June 2010 for more flexibility using 1,2,3,4 and 15
Revised 2 June 2004 to add -10, -11, 12 and -15

SSID's have seen two different uses in APRS.  Initially as an ICON
indicator back in the early 1990's.  But that is obsolete for over
a decade.  Now SSID's are used as an informal way of indicating one 
of several different typical APRS applications.

Since many small displays for the handheld and mobile operator show
nearby APRS station callsigns that flash up on the screen, it is nice
to have some idea of what type of station or activity might be 
involved simply from the callsign SSID without having to push 
buttons, search lists, or look at maps to find out more about them.  

SSID RECOMMENDATIONS:  It is very convenient to other mobile 
operators or others looking at callsigns flashing by, to be able to 
recognize some common applications at a glance.  Here are the 
recommendations for the 16 possible SSID's (the limit of 16 comes 
from the 4 bits available in the AX.25 protocol.  Note, The SSID of 
zero is dropped by most display applications.  So a callsign with no 
SSID has an SSID of 0.

-0 Your primary station usually fixed and message capable
-1 generic additional station, digi, mobile, wx, etc
-2 generic additional station, digi, mobile, wx, etc
-3 generic additional station, digi, mobile, wx, etc
-4 generic additional station, digi, mobile, wx, etc
-5 Other networks (Dstar, Iphones, Androids, Blackberry's etc)
-6 Special activity, Satellite ops, camping or 6 meters, etc
-7 walkie talkies, HT's or other human portable
-8 boats, sailboats, RV's or second main mobile
-9 Primary Mobile (usually message capable)
-10 internet, Igates, echolink, winlink, AVRS, APRN, etc
-11 balloons, aircraft, spacecraft, etc
-12 APRStt, DTMF, RFID, devices, one-way trackers*, etc
-13 Weather stations
-14 Truckers or generally full time drivers
-15 generic additional station, digi, mobile, wx, etc

* One-way trackers should best use the -12 one-way SSID indicator
because the -9's usually mean a ham in full APRS communication
both message and voice.  The -9's can be contacted by APRS message
or by Voice on his frequency included in his beacon, or on Voice
Alert if he is in simplex range.  The -12's are just moving Icons
on the map and since they have no 2 way communication for ham radio
they are not generally of routine interest to other operators.

OBJECTS or INTERNET:  In addition, Objects or internet generated 
stations can have any SSID, not just the original 16, since 
Objects are not constrained by the AX.25 header and can have a 
9 byte name.  Here are some common OBJECT/Internet SSID's:

-63 for PSK63 HF stations
-tt for APRS TouchTone users (DTMF)
-ID for RFID
-A through -Z for Dstar

SSID BACKGROUND:  Originally, in 1992, we had to use the SSID as 
a way of indicating the type of station that transmitted a raw 
NMEA-0183 GPS sting.  But in the mid 1990's we began indicating 
any of the nearly 200 APRS symbols by the setting of the AX.25 
TOCALL of "GPSxyz".  The "xyz" characters define the symbol from 
the standard APRS symbol table

The GPSxyz concept worked so well, the original SSID associations 
are no longer a required part of the spec.  But the conventions
that evolved from those early SSID's are still encouraged as 
noted above, for easy recognition of station type or activity by 
when only the callsign is seen.

The -1, -2, -3, -4 and -15 are kept generic so that anyone with
as many as 6 digipeaters, or 6 trackers or 6 weather stations or
6 vehicles can still have unique SSID's for each of his stations.
Beyond 6, people will just have to use any SSID that suits their
fancy.  In some areas there might be 15 digipeaters all under
one guy's call!

SSID USAGE:  The SSID's also might give a hint as to how someone 
is getting into APRS whether via satellite, a one-way tracker, a 
mobile, an HT or even via DTMF or an RFID device or whether he is 
doing something special.

For example, if you are doing something special, change your 
SSID to -6 to alert others to your excitement, or to make the
track-history begin and end on site, and not be tied to all 
your other -9 travels.  Or use -6 SSID for a packet sent 
via the ISS or APRS satellite or for a 6 meter test so the
successful packet is preserved and not overwritten by the same
radio the next time you use it not via the ISS on the 144.39 
national channel.  By using separate SSID's the WEB data bases 
will keep statistics and data separate from when you are working 
normally on other bands with other SSID's.

So stick to the suggestions above for the obvious applications 
where you can.  Of course these are not rigid.  If you have 
more than 6 digipeaters, use any SSID you want.  These are only 
guidelines to hint at a station's possible application when all  
you can see easily is the callsign on a screen or in a list....

de WB4APR, Bob

TX-enabled IGATES not harmful

.. food for thought....
note 1 :  I don't know why this isn't valid advise for any APRS software. 
note 2 : see point 2 below, you have to beacon out and be heard by the igate before they start transmitting you traffic. 

Sunday, October 3, 2010

Summary on UIView and IGates by WA8LMF

1) UIview does an excellent job as an igate. Contrary to the previous posting on this thread that two-way igates are difficult to set up, the default settings in UIview make it almost trivial to place a two-way igate on the air with next-to-zero impact on the RF channel.

2) Two-way igates DO NOT indiscriminately flood the RF channel with traffic from the APRS Internet System. Unless you go out of your way to explicitly edit a control file in UIview, the program only "reverse-gates" (i.e. Internet-to-RF) messages addressed to specific callsigns --- NOT generic APRS traffic such as WX beacons and position reports that are "broadcast" to everyone, and not reverse-gate to stations that are not in the immediate area.

3) On the "Setup, APRS Server Setup" dialog, locate the area in the upper right of the dialog that says "Gate RF To Interenet". Check "Open the gateway" and "Insert station callsign". In the area just below this ("Gate Internet To RF"), check "Gate local messages" and "Use reverse digi path" .

4) The option "Use reverse digi path" causes UIview to override the normal "Unproto Address" digi path set in "Setup, Station Setup" for the station's own beacons, when reverse-gating messages. Instead, messages sent to stations heard by the igate directly (i.e. not via digipeaters) will be transmitted to RF with NO DIGIPEATER PATH AT ALL.

5) Messages will be reverse-gated IF and ONLY IF the destination station has been heard on RF locally (either direct or within one digi hop) --- and --- if the destination station has been heard on RF by the igate recently (within the last half hour).

6) This process of selectively reverse-gating on a minimal path works both for messages originated by the RF (mobile) station, and for messages originated by the Internet party.

7) It even works for a station on RF in one part of the world (say on the East Coast or in Europe) working a mobile on RF in another part of the world (say the West Coast). That is a message path can go RF<-->Internet<-->RF in a manner similar to a station on RF in California talking to a mobile in Europe via EchoLink or IRLP.

The same reverse-gating rules apply: If the RF stations on each end are both local to their respective igates, and have both been heard by their respective igates recently, then two-way messaging will work. Otherwise, reverse-gating will not happen.

8) As a mobile travels cross-country, it will move out of the local range of a given igate, and into the range of another one. When an igate stops hearing the mobile LOCALLY (it might still hear the mobile via several digi hops), the digi will then age the mobile's call out of it's table of "recently heard stations" and will stop reverse-gating any messages to/from that mobile. Hopefully by this time, the mobile is now within the "local" range of another igate which will take up the task of reverse-gating. [This process is very similar to a traveler with a cellular phone moving from one cell site to another.]

Note that the stations in question don't have to be messaging for these decisions to be made. The igates make the determination of "local" and "recently heard" based on the periodic "one-way" position beacon transmissions the station is normally making anyway.

8) One-way igates break this symmetry of send/receive. A mobile originating a message will get INTO the Internet system through a one-way igate, but the reply (ack) can't get BACK to him. The originating mobile responds by cluttering the RF channel with endless automatic repetitions of the message in a vain attempt to get an ack back. In other words, one-way igates can create MORE congestion than two-way ones!

Further the Internet (or remote RF station) being messaged can't reply to the incoming message he just received.

Stephen H. Smith wa8lmf (at)
Home Page:

APRIL OK Statewide APRS net

... great success guys.

Thanks to all the stations that participated, some via UI-VIEW, some via APRSIS32 , others by smartphone app, etc. 

Let's do this again in about a month.  I'll have OBJECTS and BULLETINS going out from KD5NJR-6 once a date is established. 

In my log I have the following stations :

Let me  know if I missed anyone.

73 de Scott KD5NJR

Monday, April 6, 2015


Set FLDIGI to 7036 and PSK-250.  Do you see anything that looks like compressed APRS packets ?

If you do, proceed on to the installation of BPQ32 and BPQAPRS.  Jeff's 40m gateway is UP !

Wednesday, April 1, 2015

something interesting from the AMSAT BBS

----- Forwarded Message -----
From: "W5KUB Broadcast" <wa5kub.video9 at>
To: "Tom Medlin" <wa5kub.video9 at>
Sent: Tuesday, March 31, 2015 11:38:14 AM
Subject: Amateur Radio Roundtable

Reminder - Amateur Radio Roundtable, a live weekly ham radio webcast can be
seen at W5KUB. <>*com* every Tuesday night at 8:00 PM CDT
(0100 UTC Wednesday).

The show covers all aspects of ham radio; such as, balloon launches,
Satellite, go-kits, emergency communications, SDR, digital modes, DXing,
home brewing, and much more. This week’s guests include:

Russ Woodman, K5TUX, discussing Linux and open source for ham radio

Brian Schell, KD8OTD, author, discussing D-star and Echolink for beginners

Glen Popiel, KW5GP, author of the book “Arduino for Ham Radio”

To watch Amateur Radio Roundtable go to, click on Live Events and
sign in with your existing User Name and Password. If you don’t have a user
name and password, just enter your call or name, leave the password blank
and hit sign in.

We need your help with topics. If you have a specific subject that you
would like to present in a future show, send an email to tom at

Join us for fun and interesting ham radio discussions.  We’ll see you on
the webcast!

Tom Medlin, W5KUB

checking your APRS messages via the Internet

Like most of us, I have a job across town from where my radios are.  How would I know if someone sent me an APRS message ?  How can I see if my station is sending APRS messages ?  IF there are APRS I-Gates (Internet Gateways) in-place and up and running this is just a matter of checking the website.  Try this link and check on my station.  Make the appropriate substitution of callsigns and then check up on yours too.  73 de kd5njr / scott.

ANSRVR experiment

To start the "chat group" KT5DIG I sent an APRS message to ANSRVR with the body of the message reading CQ KT5DIG test from scott.  Interested parties might do the same to join the KT5DIG group.  Then, if you want to send a single message to reach the whole TDRC gang via APRS, you'd send a message to ANSRVR starting with CQ KT5DIG .... and that would save you from making individual APRS messages to folks...   73 de kd5njr/scott


If you've see the post "Tulsa tornado" chatter about APRS on Facebook, you likely know this already, but have kd5njr-6 running as my laptop, FT-817, rig blaster plug 'n play hardware paired with UZ7HO and APRSIS32 for software.  It's transmitting a bulletin ( when I remember to turn it on, typically weekends) APRS NET advertising the Oklahoma Statewide Net at 1300 CDT on April 11 , 2015 ( Saturday ).  The nationwide APRS frequency is 144.390 .... more to follow on the Net....


It's nice when software just works.  So I'm happy to give a plug for CHIRP.  It easily helped me set up some memories in my FT-817.  Now, if only charging the internal battery wasn't such an odd procedure.....  73 kd5njr / scott.