Looks like I am going to have make my own cables again. I dug up my
old instructions on this, and thought I would post here. It is
several years old,
--
Andy K3UK
www.obriensweb.com
(QSL via N2RJ)
Kenwood TM-D700A to Digitraveler Hook-Up :(Version 2)
Here is an explanation of how to easily connect your Kenwood TM-
D700A radio to the Radio Shack Digitraveler GPS Unit (PDA version).
These GPS devices have been discontinued by Radio Shack but if in
stock they are selling for $29.97, a very cheap way to get into APRS
with GPS. They may be even cheaper on Ebay
There are several links on the Internet that explain how to connect
the Digitrveler and the TM-D700A, , the ones I read were frequently
overly complicated, or left out important information. This is the
easy, "dummies guide"
Kenwood TM-D700A Radio Set-Up
First, you will need to set up your Kenwood TM-D700A to allow APRS
capability. The essential items are:
Make sure "TNC-APRS" is indicated on your Kenwood TM-D700A display.
(If not , use your manual to learn how to enable this feature).
Make sure that "Bcon" is indicated on your Kenwood TM-D700A
display. (If not , use your manual to learn how to enable this
feature).
Make sure that "GPS" is indicated on your Kenwood TM-D700A display.
(If not , use your manual to learn how to enable this feature ).
Also, make sure your GPS settings in the Kenwood TM-D700A's sub-menu
are set at "NMEA" . The Kenwood manual explains how to do this.
Make Sure that "1200" (packet baud rate) is indicated on your
Kenwood TM-D700A display. (If not , use your manual to learn how
to enable this feature ). 1200 is the default baud rate for the
radio, so this should already be set.
Connecting the Kenwood TM-D700A to the Digitraveler GPS Device.
Cut the PDA connector off one of the cables supplied with the
Digitraveler (the PDA version of the Digitraveler comes with THREE
connector cables, so you can make three cables if you want!) This
will leave you with a cable that has a RJ-45 connector at one end,
and three bare wires at the other end. You will have a Red wire, a
Black wire, and a Brown wire.
Next, locate the cable that is supplied with the Kenwood TM-D700A.
This is a long thin cable with a sub-miniature plug on one end ,
and three bare wires on the other end. The Kenwood supplied cable
has wires that are white, red (may look orange to some eyes), and
bare wire .
I tried temporary connections of the above three wires to the GPS
wires and twisted them together. This was a major mistake since the
wires of the Kenwood radio are so thin and contain non-conducting
fibers within the copper strands. The result was that I was not
making a good electrical connection between the Kenwood and
Digitraveler cables.
So, to avoid the above ... first "tin" thoroughly, the Red, White,
and ground wires on the Kenwood cable. Double check for good
continuity by taking a multi-meter and connecting the probes to the
bare ends of the Kenwood wires. Check a few places along the length
of the bare wires that you stripped back.
Now, connect the supplied Kenwood TM-D700A cable to the
Digitraveler cable. as follows:
Red wire on the Kenwood to the Brown wire of the Digitraveler
White wire on the Kenwood to the Red wire of the Digitraveler
Bare ground wire on Kenwood cable to the Black wire of the
Digitraveler.
That's it! At least as far as the connection goes.
Getting power to the Digitraveler:
The next step is getting power to the Digitraveler. You can simply
insert 3 AAA batteries in the Digitraveler or an alternative 6 volt
DC supply. Since I use mine in the car, I purchased a cigarette
lighter device that drops the car's 12 volts down to 6 volts. I got
mine from Radio Shack , it included a free coaxial power connector.
I selected the "Type B" connector which fits the Digitraveler.
You should take the cable you made up, plug in the RJ-45 connector
in to the Digitraveler and the sub-miniature plug in to the back of
you Kenwood TM-D700A in the jack marked GPS.
With your radio on and power connected to the Digitraveler, you
should see the Green LED on your Digitraveler light up. If it does
not, re-check the connections you made on the cable and double check
you have power supplied to the Digitraveler. If the green light is
on, you're all set. The Digitraveler will need a few minutes
to "lock-on" to the GPS satellites. My experience has been that it
can take 2-3 minutes on the first occasion, sometimes longer if it
is a very cloudy day. Make sure your Digitraveler is in a position
that allows it to easily see the GPS satellites. It generally does
not work inside your home or office. If outside make sure that
there are no trees above your vehicle.
Within a couple of minutes, you should notice the "GPS" display on
your Kenwood TM-D700A begin to flash. If it flashes, Eureka !
That's it.
You can press the Function button on your Kenwood, hold it down long
enough (two beeps) to see the APRS menu. Select "position"
