Frequently Asked Questions
A: You will need to add a serial port to the computer to be able to connect it to a TNC. There are several companies making serial port adapters that connect to the computer through the USB port. Most require that the operating system in the computer be Windows 98 or later (or a Mac OS). Once that serial port has been connected to the computer and recognized by the operating system in the computer, it should be available for any Windows (or Mac) terminal program to use to communicate with the TNC.
A: For older model TNCs (KPC-1/2/2400/4, KPC-3 and KPC-9612 (non Plus models), KAM and KAM Plus, and DATA ENGINE), no. In many cases, components used in manufacturing those units have been discontinued by their makers, and are no longer available.
Repair service has been discontinued for units more than 10 years old, including:
The Interface and Interface II, UTU, UTU-XT, UTU-XT/P, Challenger, Field Day and Field Day II, Mini-Reader, Vari-Filter, etc.
A: Over time, the filter capacitors in the KAM can dry out or suffer some damage, causing the considerable ripple in negative voltage supply in the KAM. Replacing these capacitors usually solves the problem. The capacitors in question are on the front edge of the KAM PC board, located between the bargraph and the switches. Both capacitors are 10 microfarad electrolytic, rated at 50 volts or more, but a cap with 35 volt rating will work.
Replacements can be found at Radio Shack or many other parts houses.
A: New Kantronics TNCs, when first powered up, will perform an autobaud routine. The TNC must first be initialized using your computer or terminal, by setting an interface baud rate and entering a callsign. Until it has been initialized, the TNC will not show any signs of activity other than its power led.
A: The TNCs can have as many as 26 connected links (in converse mode) going at once. The maximum number of connections is controlled by the command MAXUSERS, which is default to 10. The TNCs keep track of the connections with a stream identifier (see streamswitch).
A: When using a transceiver, it can only transmit or receive, and can not do both at the same time. This is half duplex communication. Full duplex communication requires both a transmitter and receiver (each using a different frequency.)
A: No. But, each port of a multi-port TNC can have as many as 26 converse connections at one time (as allowed by the MAXUSERS command). Only one connected link in transparent mode is allowed at any time.
A: There are three basic methods of connecting your TNC to a hand-held radio. The three diagrams shown in your Kantronics TNC manual apply to most hand-helds, even though we show only the Icom, Kenwood, and Yaesu.
Kenwood handhelds produced since the TR-2600 (about 1985) all use the diagram shown in the manual. Yaesu handhelds produced since the FT-727 (about 1985) all use the diagram shown in the manual.
Most other hand-held radios use the wiring diagram shown for the Icom with a possible change in the resistor value. If the resistor value you use is too high, the radio will not go into transmit mode, and if it's
too low, the radio will transmit, but you will not be able to hear any packet sounds. If the "other" handheld has two plugs for the speaker-mic, use the diagram for the Icom 2AT style; if it has just one
plug, use the diagram for the Icom W2A style. The LINKS page of our website lists several other sites with useful wiring diagrams. One site is www.packetradio.com.
A: Most current production base radios use a round 8-pin or modular microphone connector. The diagram is provided in the Kantronics TNC manual for Icom, Kenwood, and Yaesu radios with round 8 pin microphone connectors. If you have another brand of radio, the basic wiring is as follows:
- AFSK (transmit signal) from the TNC to the microphone input pin.
- PTT (push-to-talk) from the TNC to PTT pin (or STBY pin).
- Ground from the TNC to ground on the radio.
- Receive input to the TNC from the external speaker jack on the radio.
Many TNC to radio wiring diagrams or ready-made cables can be found on the internet and from other sources. One site is www.packetradio.com.
A: This is the status indication when the TNC has been left in Host Mode. It usually occurs after running a host mode software program such as HostMaster, or PacTerm98 (or PacTerm Windows). To exit the Host Mode and return to the command prompt, use a standard terminal program such as Pacterm or Procomm Plus to send the host mode exit string.
Use the following three steps to exit Host Mode:
- Hold down the ALT key on your keyboard and type the number 192 on the keypad (not the keys above the keyboard). Release the ALT key.
- Type the letter Q.
- Hold down the ALT key on your keyboard and type the number 192 on the keypad. Release the ALT key.
A: Yes. When enabled, the PBBS in the TNC is active all the time. It will answer to other stations whether or not a terminal is connected to your TNC. You can also cause an automatic switch to the PBBS when stations connect to your TNCs MYCALL (see the CMSG command).
A: You may have turned off your computer or disconnected it from your TNC, but you left the TNC command called MONITOR set to ON. Be sure to set MONITOR to OFF, before turning off your terminal or disconnecting it from your TNC.
A: No. The modem circuit in the KPC-3 Plus is only for 1200 baud. To do any higher baud rates over the radio, use one of our other TNC models such as the KPC-9612 Plus or KAM XL. Higher baud rates can only be done through a radio with the proper internal connections and bandwidth. For example, 9600 baud requires that the audio bandwidth of the radio channel be at least 5 to 8 KHz. The connections must be direct to modulator stage for transmit, and direct from discriminator stage for receive (must bypass all audio filtering circuits.)
A: KaNode is a simple node (is not a network node). Other stations connect to a KaNode station, and then command that KaNode to connect to a destination (or another node) that they can not reach directly. See K-Net for the NetRom compatible network node function.
A: Kantronics has developed a network node function called K-Net, that is functionally compatible to NetRom and TheNet nodes. It is included as a standard feature in current model TNCs such as our KPC-3 Plus, KPC-9612 Plus (and 9.1 updates for them), and KAM XL.