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Frequently Asked Questions

Q: How do I connect a TNC to my new computer that does not have a serial port?Skip answer

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.

Q: What firmware updates are available for old TNCs?Skip answer

A: Firmware updates for older model TNCs (KPC-1/2/2400/4, KPC-3 and KPC-9612 (non Plus models), KAM and KAM Plus, and DATA ENGINE) have been discontinued and are no longer available from Kantronics.

Q: Is factory repair service still available for my old model TNC?Skip answer

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.

Q: Recently, my KAM has started displaying garbled characters on the screen. It looks like machine language.Skip answer

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.

Q: I just connected my new Kantronics TNC to the radio, and when I hear packets, the receive LED doesn't light.Skip answer

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.

Q: The tuning bargaph on my KAM XL does not light after it has been initailized.Skip answer

A: In the factory default settings, the KAM XL HF packet port is not enabled. Enable HF packet by setting the command HBAUD to a packet baud above 0 (usually 300).

Q: If using the connection mode, can you have more than one connection active at the same time, to separate radios?Skip answer

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).

Q: Is a packet connection between two TNCs full or half duplex?Skip answer

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.)

Q: Do I need a multi-port controller to get multiple simultaneous connections?Skip answer

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.

Q: How do I connect my Kantronics TNC to my handheld radio?Skip answer

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.

Q: How do I connect my Kantronics TNC to my base radio?Skip answer

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.

Q: I can't get a command prompt from my TNC. All I get is some funny characters that look like two little L's followed by S00, then another little L.Skip answer

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.

Your TNC should now be out of Host Mode.

Q: Is there more information available for receiving POCSAG pages with my KPC-9612 Plus?Skip answer

A: The manual for the KPC-9612 Plus contains information about enabling POCSAG page monitoring mode.

Q: Can I leave my TNC and radio on and still receive mail messages even with the computer off?Skip answer

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).

Q: Why do other stations receive a BUSY message, when they connect to my TNC or its PBBS?Skip answer

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.

Q: Can I do 9600 baud through a radio with my KPC-3+?Skip answer

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.)

Q: Does the KANode function perform any network routing like a NetRom type node?Skip answer

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.

Q: Can I use NetRom in a Kantronics TNC?Skip answer

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.

Q: Do I need anything special to work packet with DAMA stations?Skip answer

A: DAMA mode has been a standard feature in Kantronics TNCs since version 8.2.

Kantronics  •  14830 West 117th Street  •  Olathe, Kansas 66062
Phone (913) 839-1470  •  Fax (913) 839-8231  • 
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