[aprssig] Re:All APRS Digipeaters In The World (Almost!) Mapped On UIview

Stephen H. Smith wa8lmf2 at aol.com
Fri Mar 2 14:30:05 EST 2007

zl2tze at yahoo.com.au wrote:
> Hi,
>      Well done Stephen..
> FYI NZ has far more digis than shown.
> Many NZ station act as a Gateway / Node / Digi but would in most cases use
> either Gateway or Node with a few dedicated Digi. These stations are mainly
> owner operator with a few club operated digis.
> The problem is that there is no Multi Task symbol for the station that does
> all 3 things Gateway / Node / Digi etc Maybe a Multi Task symbol could be
> produced :-)
> In reflection your Map of NZ would be missing over 2/3rds of the available
> APRS Digis available to users.
> This could also be a problem for your WW map as you only collected data with
> a STAR Symbol, others around the world may be doing the same, and using a
> symbol that reflects there primary use only.

Since digipeater operation has a greater impact on surrounding users 
than any other station activity (i.e. weather stations and igates don't 
generate multiple transmissions after OTHER stations transmit), I would 
tend to think that any multi-tasking station should give priority to the 
digipeater symbol.  

I suppose one kludge solution would be to connect a TinyTrak in parallel 
with your main TNC.  Set the TT to the same callsign as the main 
station, and set it to alternately beacon primary and alternate settings 
with a different symbol selected in each side. For example, the main TNC 
could be set to beacon "DIGIPEATER", the TT primary could be set to 
"IGATE" and the TT secondary to "WX".   This would even give the option 
to use different paths  (i.e. direct, one hop, or two hops)  for each 
symbol if desired.   You would have to use a diode matrix to combine the 
main TNC's CD and PTT lines into the TT CD to prevent the TT from keying 
up when the main unit is either receiving or transmitting.

This is one place where a standalone KPC3+  or UIdigi-equipped TNC2 has 
a real advantage over most programs on a PC,  since you can set three 
different beacon texts, each with it's own repetition rate, path and 
symbol.into these devices.(Running one of these TNCs in KISS mode with a 
PC would suspend their built-in beacon text transmissions.)

Note however that the "pileup" problem I noted in a response to a 
previous ZL's post still applies.  If a station at a single location 
sends several different symbols alternately, they will wind up directly 
on top of each other.  Only the most recently sent one will be 
visible.      (I often see this here in Los Angeles where a home station 
"fights" with a car parked in the driveway.    In the daytime, when the 
car is at work, you see a constant house.  At night, you see 
House-Car-House-Car ... on the map.)       [ This wouldn't be a problem 
for my particular mapping undertaking since I am filtering by digi 
symbol; other symbols at the same position would be ignored.]


Stephen H. Smith    wa8lmf (at) aol.com
EchoLink Node:      14400    [Think bottom of the 2M band]
Home Page:          http://wa8lmf.com  --OR--   http://wa8lmf.net

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