Thanks to all who replied. In the end, I never got it working. It appears to
be a basic incompatibility between the Garmin GPSmap 60 and the TinyTrak3. I
should have done better research into exactly which GPS models are
compatible with the TinyTrak3.

An exhaustive search of the Internet turns up absolutely no information on
incompatibilities between the TinyTrak3 and the vast number of GPS units on
the market today. But neither could I find any complaints of people running
into incompatibility problems. Strange.

Incidentally, the latest generation of Garmin units have only USB ports, no
more serial ports. By definition, all of these are incompatible with the
TinyTrak3.

I have a feeling that the TinyTrak3 hasn't kept up with the times and if it
expects to survive it has to be updated to allow operation with the latest
NMEA protocol version and the new USB units.

The TinyTrak is a good idea. I hope it gets updated, and I hope to see a
section on its web site with information about which GPS's are okay and
which ones to avoid.

Regards,

Al W6LX







"Anonymous" wrote in message
...
Hi, Everybody,

I am trying to set up an APRS station consisting of a Garmin GPSmap 60 and
one of the TinyTrak3 TNCs. However, the green 'GPS Valid' LED never
lights.

I can connect the GPS receiver directly to my computer's serial port and
read good data, and I can capture some of that data and play it back from
computer to TinyTrak and the green LED lights up, but a direct connection
between GPS and TT just does not work.

I see a waveform coming out of the GPS serial (J2 pin 2 of the TT) using a
scope. Quiescent voltage is -5V, and when the data burst comes it is -5 V
to
+5 V.

Could this be a voltage level problem on the serial? Is there a converter
that can be used? Or is it another problem, possibly protocol-related?

Any ideas?

Thank you,

Al W6LX