[CALV-AUXCOMM] Net in Lieu of AUXCOMM Meeting on Dec 19

[Shawn Donley]

All,


With the busy holiday season upon us, we will have a net on the 146.985 repeater on Tuesday, Dec 19th instead of a meeting.   The net will meet at 7:30 PM.


After the voice net, I'd like to try a digital round table using packet on 145.750 MHz with our digipeaters to extend range.  This will be a repeat of the "unconnected" packet test we ran a few months ago.  I'll act as net control.  Some details on how to set up your TNC and use it in unconnected mode appears below.


Break-Break ... in other news, the Region V hospital exercise date has been moved from May 18 to May 2, 2018.  Further details coming out later.


Have a enjoyable and safe holiday.


Shawn

N3AE

Calvert EC


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


Unconnected "Round Table" TNC Setup


In the manual for your TNC, the "Round Table" feature is called "UNPROTO". To operate in this mode, you will need to modify some of the settings on your TNC.  Using whatever terminal program you prefer to interface your computer to your TNC, set the parameters as shown below.  An explanation of these parameters is at the very end of this email.


MCOM ON
MONITOR ON
PACLEN 72
UNPROTO ALL VIA K3CAL-10


Once you have yor TNC parameters set, you enter the unconnected or round table mode by either typing in the letter K or the string CONV followed by the enter key on your keyboard.  This puts the TNC into Converse mode.  After doing that, anything you type will be sent out on the radio when you hit the enter key and digipeated by K3CAL-10.  You should see your digipeated text appear on your screen.   I picked K3CAL-10 rather than K3CAL-1 because -10 is more centrally located.  


For example, if I had typed in the string Hello to All Calvert AUXCOMM Members, this is what should show up on your screen (and everyone's screen) as K3CAL-10 digipeates the message).


              N3AE>ALL,K3CAL-10* <UI R>:Hello to All Calvert AUXCOMM Members


The <UI R> is a code for the type of packet frame being received.,,,explained at the bottom of this email.


In "unconnected" mode, there is no error correction or automatic request for repeats.  So if your signal is weak or someone else decides to transmit at the same time you do, the string may not make it through the digipeater.


To exit Converse mode, hold down the control key and type the letter C.  You should see cmd: on your screen.


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


Explanation of TNC parameters (for those interested in knowing):


MCOM: ON
Set this value on to monitor all data. Set this value "ON" if you want to see the details of every single
packet. This is very useful while monitoring unconnected packets.


MONITOR: ON
Allows monitoring of packets while not connected.  This is essential for the "unconnected" round table type operation.


PACLEN: 72 (Characters per line)
Short data packets are less likely to be clobbered or corrupted. The typical setting for connected mode is 128, but for unconnected operation, 72 may work better, particularly if your signal or the other station's signal is not strong.


The UNPROTO command has several parts. The first part is the TOCALL and should be one of the generic callsigns recognized by most other software programs such as CQ, ALL, APRS, QST.   We will use ALL. The second part is the letter V or the word VIA and the third part is the PATH. For our net this should be K3CAL-10, our digipeater in Prince Frederick


Explanation of packet frame types:


AX-25 packet frame conventions:
You should try to become familiar with a few of the packet frame identifiers, this will help you understand, what you are seeing. Some of this information should be in your TNC's users manual.  So in the example above where I sent an "unconnected" string, the UI in the <UI R> tells you what follows is a packet received from a station you are not currently connected to. 


C-Connect request
D-Disconnect request
DM-Disconnect mode
UA-Unnumbered Acknowledge
UI-Unconnected Information frame
I(n)-Information frame (n=0-7).