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Wed Nov 18 21:02:00 UTC 2009


And when you report for duty at the EOC, or ham club, or local
bar, everyone will know.  If you don't want them to know, jump
over the door mat!

Maybe the ARRL will start stocking ARRL "Name Boots"... Instead
of Name Tags...

Bob, WB4APR

 
> 
> Quoting Robert Bruninga <bruninga at usna.edu>:
> 
> > I still think APRS-RFID... Is a next thing for APRS
> > experimenting
> >
> > Every ham hat could have a $2 chip in it.
> >
> > Then we can tell who enters the clubhouse or EOC... (it gets
> > converted to APRS...)
> > See http://www.aprs.org/aprs-rfid.html
> >
> > Problem is, the maximum range reader I can find is only good
for
> > 10 inches max and it costs about $24:
> >
http://www.sparkfun.com/datasheets/Sensors/ID-12-Datasheet.pdf
> >
> > It has provisions for a  wind your own antenna but still can
> > only get to about 10 " (25cm).  But since hams are RF
> > experimenters, it would seem that we could improve on this.
One
> > sentence in the limited docs says that there has to be
enough
> > energy to activate the chip.  This implies to me that the
limit
> > is on the energy transmitted to the chip, not necessarily
the
> > read range.  Frequency is 125 KHz.
> >
> > To get reliable coverage for people walking through a door,
I
> > think we need about 48" range...
> >
> > Does anyone want to fill us in on the details?  I assume a
125
> > KHz carrier in the antenna coil provides the energy for the
RFID
> > chip (this can be scaled up... Just needs more power)...
But
> > then I guess it has some off cycles so the chip can send
back
> > the 32 bit code?
> >
> > Bob, WB4APR
> >
> >
> > _______________________________________________
> > aprssig mailing list
> > aprssig at tapr.org
> > https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig
> >
> 
> 
> 




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