Order Tray | Contact Us | Home | SIG Lists

[aprssig] DTMF encoding

Robert Bruninga bruninga at usna.edu
Wed Oct 1 17:55:21 UTC 2008


> Ok, so they don't use pauses for LOCAL entry, 
> what is the APRStt proposal for what actually 
> gets stored and/or transmitted from the DTMF 
> memory?  If we store the pauses...

You store the A key. (or C key depending on what we decide
kenwood is up to with the use of the A key on the D7 and the C
key on the D710 for the same function...)

> Seems like the deterministic 2 digits per 
> character (12 per callsign) seems to win...

Yes, and with Q now on the 7 key, it takes 1 more key press now
for Q R S and 7!  So for callsign entry into APRStt (which it
knows it is looking for), I propose that the NUMERIIC in all
callsigns should be preceeded with the "0" key.  SO instead of
WB4APR being 922444427A777 which takes 13 bytes, that the 4444
is sent as 04 for only a total of 11.

To actually use a "0" in a callsign, then it has to be "00".

Pitty the poor guy with the callsign of FF3SSS...
333A333A33337777A7777A7777

BUT!!!  APRStt is by definition, a SIMPLEX RANGE LOCAL Function
(or input to a repeater)... So LOCAL CONVENTIONS (for shortcuts)
are possible.  Since most calls in France begin with F (333), I
would think that for a one-by callsign F5XXX, then if the code
received on a LOCAL frequency (by convention) was 305... That it
could be interpreted as F# for example.  Though the full 3335555
would always work.

Bob, Wb4APR

> Robert Bruninga wrote:
> > The D7 and D700 do not use pauses.  When you change keys (in
the
> > multi-press system), then that means you are moving on to
the
> > next letter.  If the next letter is on the same key, then
you
> > press the right-shift button ("A" key) or the RIGHt Joystick
> > button.   Now here is the amazing part.  In the D710,
kenwood
> > changed the right-shift function to the "C" key.
> >
> > Bob
> >
> >   
> >> I'm confused... about how using nnnn can 
> >> actually get the right letter without programming 
> >> pauses into the stream?  For instance:
> >>
> >> 5554444337775 = KJ4ERJ or was that L4ERJ or JJJ4ERJ?
> >>
> >> Without a display to latch on the letter and move the
cursor
> >>     
> > on the 
> >   
> >> pause, the person driving the keyboard has no clue.  Even
> >>     
> > worse (and 
> >   
> >> this is the 'nixer, I suspect) without coding the pauses
INTO 
> >> THE DTMF 
> >> STREAM, there's no way that I know of for the receiver to 
> >> know what was 
> >> actually entered.
> >>
> >> I was actually leaning in favor of this approach until he 
> >> brought this 
> >> up.  Seems like the EchoLink folks might have something
going 
> >> with the 
> >> statement that EVERY keystroke is 2 digits.
> >>
> >> 525140327351 = KJ4ERJ is deterministic at least.  You could

> >> even extend 
> >> it to cover lower-case should anyone really want to do such
a
> >>     
> > thing.
> >   
> >> 525140357654 = KJ4erj based on hitting the E key 5 times 
> >> (DEFdef) and so 
> >> forth (76=PQRpqr 54=JKLjkl)
> >>
> >> Lynn (D) - KJ4ERJ - Adding my $0.02 for whatever it's
worth.
> >>
> >> PS.  I really have trouble with the enter and pause with my

> >> last name.  
> >> There's at least once voice response system out in IRS 
> >> (Internal Revenue 
> >> Service, the US tax guys) that requires me to touch tone
the
> >>     
> > first 5 
> >   
> >> characters of my last name....
> >>
> >> DEFFE = 3...33...333...333...33# - Positively painful!
> >>
> >> jimlux wrote:
> >>     
> >>> Bear in mind when talking about multiple key presses that 
> >>>       
> >> most devices 
> >>     
> >>> that use this have some sort of visual feedback (e.g. an 
> >>>       
> >> alphanumeric 
> >>     
> >>> display).  I'd hate to have anything like this with no 
> >>>       
> >> feedback.  Hence 
> >>     
> >>> directory lookup interactive voice response systems that
ask
> >>>       
> > you to 
> >   
> >>> enter the name using a single digit for each letter (using

> >>>       
> >> the 2=ABC 
> >>     
> >>> scheme).. Hopefully that "hashes" to a unique identifier 
> >>>       
> >> that allows the 
> >>     
> >>> lookup to work. If not, they disambiguate by asking you
"do 
> >>>       
> >> you mean A 
> >>     
> >>> (press 1) or B (press 2)"
> >>>
> >>>
> >>> Jim, W6RMK
> >>>
> >>> _______________________________________________
> >>> aprssig mailing list
> >>> aprssig at lists.tapr.org
> >>> https://lists.tapr.org/cgi-bin/mailman/listinfo/aprssig
> >>>
> >>>   
> >>>       
> >> _______________________________________________
> >> aprssig mailing list
> >> aprssig at lists.tapr.org
> >> https://lists.tapr.org/cgi-bin/mailman/listinfo/aprssig
> >>
> >>     
> >
> >
> > _______________________________________________
> > aprssig mailing list
> > aprssig at lists.tapr.org
> > https://lists.tapr.org/cgi-bin/mailman/listinfo/aprssig
> >
> >   
> 
> 





More information about the aprssig mailing list