Timewave PK-900, Operating Manual

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22222 / TNC GPS Upgrade Addendum
Hardware Configurations
There are four different hardware configurations you can use when operating within an APRS
system, each for a different purpose:
1. A computer running APRS, a GPS receiver, a TNC, an APRS Adapter Cable (optional), and a radio:
This complete configuration allows you to track all users on the system in your area (including
yourself), and send/receive messages and bulletins. Using Timewave’s APRS Adapter Cable, you
can connect a GPS receiver and a TNC to a single COM port on a computer running APRS, see
Figure 2. Without the APRS Adapter Cable, the TNC and GPS receiver would need to be con-
nected to separate COM ports. Having two COM ports free on most computers is a luxury most us
don’t have with all the Windows related equipment such as mice and other serial peripherals. Mo-
bile laptop computer users need the APRS Adapter Cable because most only have one COM port.
Running
APRS
2. A computer running APRS software, any Timewave TNC, and a radio (No GPS receiver):
This configuration lets you track all users on the system with your location being entered manu-
ally. This also lets you send and receive messages within APRS. All Timewave TNCs can be part
of a system such as this. This configuration allows anyone with any Timewave TNC who is run-
ning APRS software in their computer to take part in this GPS technology. You don’t need a GPS
receiver to pull down location information from the satellites because you enter your position
manually on the APRS computerized map, which in most cases is fine because you are at your
house which doesn’t (shouldn’t) move. The only time you really need a GPS receiver is when you
are operating packet while mobile because manually updating your position while mobile isn’t
practical—you need the GPS receiver to pull in those satellite location signals and update your po-
sition as you move.
3. A TNC, a GPS receiver, and a radio (No PC):
This trio allows you to transmit your location automatically to others in an APRS system without
having a computer in the vehicle. This is known as a Stand Alone Tracking Device because others
can track your motion without you having to run APRS or even have a computer. The firmware in
the TNC allows the TNC to parse the incoming location information from the GPS receiver (with-
TNC TNC
TNC TNC
TNC
Running
APRS
FIGURE 2: APRS HSP mode where APRS controls the cable switching between the TNC and GPS receiver