DAVIS 7730 (01) PDF Document

To use the DAVIS 7730, you will need the following:

Weather Station: A Davis Vantage Pro or Vantage Pro2 weather station.

WeatherLink: WeatherLink for Vantage Pro and Vantage Pro2, version 5.7 or later.

Computer: A personal computer with an available serial port running Windows 98/ME/2000/XP.

Ham Radio: A 2-meter ham radio with a 6-pin mini DIN data port or with microphone and speaker connections. The radio should be capable of transmitting at 1200 baud.

Antenna: An antenna for your radio.

Call Sign: An FCC-granted ham radio call sign.

The DAVIS 7730 package includes the following items:

• WeatherLink for APRS program on CD.

• The DAVIS 7730 TNC (Terminal Node Controller).

• A 4-foot (1.2 m) serial cable with a DB-9 male connector on one end and a DB-9 female connector on the other.

• An audio cable (stereo) for connecting the TNC to your radio’s speaker and microphone jacks if your radio does not have a data port.

To install and connect your DAVIS 7730, please follow these steps:

Step 1: Install WeatherLink Software

If you have not already installed WeatherLink version 5.7 or later, please do so now.

1. Insert the WeatherLink for APRS CD into your computer’s CD-ROM drive. The installation program should start automatically. If it does not, run the SETUP.EXE program on the CD.

2. Follow the on-screen instructions to complete the installation.

Step 2: Connect the DAVIS 7730 TNC

1. Connect the TNC to your computer using the supplied DB-9 serial cable. Plug the male end of the cable into your computer’s serial port and the female end into the TNC’s serial port.

2. Connect the TNC to your 2-meter radio. How you connect the TNC to the radio depends on the type of connection your radio uses.

Connecting to a radio with a data port (6-pin mini DIN):

You will need a PS/2 keyboard extension cable (6-pin mini DIN, male-to-female). Plug the male end of the cable into your radio’s data port and the female end into the TNC’s Radio Port.

Connecting to a radio with speaker and mic jacks:

You will need two cables: the supplied audio cable and a second cable that matches your radio’s microphone jack. Connect the TNC as follows:

• Plug one end of the supplied audio cable into the TNC’s AUDIO port.

• Connect the other end of the audio cable to your radio’s external speaker jack using a mono-to-stereo adapter if necessary.

• Use a second cable to connect your radio’s microphone jack to the TNC’s RADIO port. You may need to build this cable yourself.

Follow these steps to configure the software to work with your DAVIS 7730:

Step 1: Select APRS Mode

1. In WeatherLink, go to the Setup menu and select “APRS Setup.”

2. Check the “Enable APRS Mode” box.

Step 2: Enter Station Information

1. In the APRS Setup dialog box, enter your ham radio call sign in the “Call Sign” field. Add an SSID if you are running multiple stations with the same call sign.

2. Enter your station’s Latitude and Longitude. You can look these up based on your street address if needed.

3. Enter any optional Comments you want to transmit with your weather data.

Step 3: Configure Communication Port

1. Select the computer’s communication (COM) port to which the DAVIS 7730 is connected.

2. Click the “Test” button. A “Serial Port Test Passed” message should appear. If not, select a different COM port and test again.

Step 4: Configure Data Transmission

1. Enter the time interval, in minutes, for how often you want to transmit your weather data in the “Transmission Interval” field.

2. Select either “Smart Beaconing” or “Fixed” for your beacon rate. Smart beaconing is recommended for mobile stations, while fixed is for fixed stations.

Step 5: Configure Packet Information

1. Enter the path you want your packets to take in the “Digi Path” field (e.g., WIDE1-1,WIDE2-1).

2. Select the symbol you want to use to identify your station on an APRS map from the “Station Icon” pull-down menu.

3. Check the “Transmit position with every weather packet” box if you want to include your latitude and longitude in every transmission.

4. Click “OK” to save your settings.

Once you have configured the WeatherLink for APRS software, your DAVIS 7730 will transmit weather data automatically. The program sends a weather data packet at the transmission interval you specified in the APRS Setup dialog box.

The first packet is transmitted after the first full interval has elapsed. To transmit a packet immediately without waiting for the next scheduled transmission, you can select “Send Now” from the APRS menu. This is useful for testing your station’s setup.

The red LED on the DAVIS 7730 will light up whenever a data packet is being transmitted.

The weather data packets transmitted by the DAVIS 7730 conform to the APRS Position/Weather Report Format. The packet contains your station’s call sign, location, a symbol to represent the station, and weather data. Weather data includes wind direction, wind speed, wind gust, temperature, rainfall, humidity, and barometric pressure.

An example packet looks like this:

N6DWI-1>APRS,WIDE2-1:_10080553c220s004g005t077r000p000h53b09910Davis Wx Station

The table below shows how weather data is encoded in the packet.

If your weather data is not being received by the APRS network when using the DAVIS 7730, check the following:

Check connections.

• Make sure the serial cable is securely connected to both the TNC and the computer.

• Make sure the TNC is securely connected to your radio.

• Make sure the antenna is connected to your radio.

Check radio settings.

• Make sure your radio is on and tuned to the APRS frequency (144.390 in North America).

• Make sure the radio’s squelch is turned all the way down.

• Adjust the radio’s volume control. If the volume is too high or too low, the signal will be distorted and other stations will not be able to decode your data packets. You may need to experiment to find the correct volume setting.

Check the TNC’s transmit LED.

• The red LED on the TNC should light up each time a packet is transmitted. If the LED does not light, the TNC may not be getting data from the computer. Check the serial port connection and settings.

Check WeatherLink for APRS configuration.

• In WeatherLink, go to the APRS Setup dialog box and verify that your call sign, communication port, and digi path are entered correctly.

Yes, you can use the DAVIS 7730 TNC with any APRS software program that supports the TNC2 format, such as UI-View. The DAVIS 7730 operates as a KISS mode TNC.

If your computer does not have any available serial ports, you can use a USB-to-serial adapter to connect the DAVIS 7730 TNC to one of your computer’s USB ports.

No, the WeatherLink for APRS software required to operate the DAVIS 7730 runs on Windows only and is not available for Macintosh computers.

The DAVIS 7730 TNC operates in KISS mode by default. You can switch to command mode to manually set TNC parameters. To do this, you will need a terminal emulation program such as HyperTerminal.

Entering Command Mode:

1. Start your terminal program and configure it to use the COM port to which the TNC is connected. Use the following port settings: 9600 baud, 8 data bits, no parity, 1 stop bit, and no flow control.

2. To switch the TNC from KISS mode to command mode, you must send it a specific three-character sequence. The sequence is: Ctrl-C, followed by a null character (ASCII 0), followed by Ctrl-C again.

3. If successful, the TNC will respond with `cmd:`, indicating it is in command mode.

Exiting Command Mode:

To exit command mode and return to KISS mode, type `KISS ON` and press Enter. The TNC will respond with `KISS is ON` and return to KISS mode. To save any changed parameters to non-volatile memory so they are retained after a power cycle, type `RESTART` instead.

The following commands can be used when the DAVIS 7730 is in TNC Command Mode. Type the command and press Enter. To display the current value of a parameter, type the command without a value. Note that commands are not case sensitive.

If you need to make your own cable to connect the DAVIS 7730 to your radio, you will need to know the pin assignments for the TNC’s RADIO port and your radio’s microphone or data connector. The pin assignments for the TNC’s RADIO port (an RJ-11 connector) are as follows:

• Pin 1: Mic Audio In

• Pin 2: Ground

• Pin 3: Push-to-Talk (PTT)

• Pin 4: N/C (No connection)

• Pin 5: N/C

• Pin 6: N/C

Below are the pin-out diagrams for common microphone and data connectors. You must connect the Mic Audio, Ground, and PTT lines from the TNC to the corresponding pins on your radio’s connector.

RJ-45 (8-pin modular) Connector:

• Pin 1: Mic Audio In

• Pin 2: +8V

• Pin 3: Up/Down

• Pin 4: PTT

• Pin 5: Mic Ground

• Pin 6: Ground

• Pin 7: N/C

• Pin 8: N/C

6-pin Mini DIN Connector:

• Pin 1: Data In (from TNC)

• Pin 2: Ground

• Pin 3: PTT

• Pin 4: Data Out (to TNC)

• Pin 5: AF Out (to TNC)

• Pin 6: Squelch

DB-9 Connector:

• Pin 1: Mic Audio In

• Pin 2: Squelch

• Pin 3: PTT

• Pin 4: N/C

• Pin 5: N/C

• Pin 6: N/C

• Pin 7: Ground

• Pin 8: +8V

• Pin 9: N/C

Always consult your radio’s documentation to verify pin assignments before making any connections.