What's TNC anyway

[Shiloyboy]

Hello, I am new to ham. I got my license years ago but never started until now using it. I am going to upgrade to General with the test in a couple of weeks. I wanted to know exactly what is it you can do with your computer, radio and the TNC? Do you essentially talk to people on your computer using your radio at the "modem", like on the internet now? Sorry for dumb question. Shiloyboy

 

[n8fgb]

TNC, terminal node controller. Radio modem for use on digital modes like packet.
Rich

 

[Qwazyone]

If you have studied for the general test, most of the info should be there(should is the key word). A lot of the digital modes do not require a TNC, BPSK-31 just needs an interface between your computer and radio to work basically to isolate any RF from the PC from the rig or vice-versa

Never a dumb question, unless you're asking Jeff Foxworthy

 

[ke7vvt]

From my limited experience, a TNC is the modem used to decode APRS data. If you tune to 144.390 you will hear a bunch of the sounds from back in the day when you had to dial up to get connected to the tubes, the TNC decodes those lovely sounds and can give that data to a computer or the transceiver display to show a text message.

There is a cool thing called EchoLink and WIRES. Radio1->Radio2 + Internet->Internet->Radio3 +Internet->Radio4 so the radio waves go to another radio connected to the internet and the signal makes its way through the tubes and back out again on another radio somewhere else. That is probably what you want to look into more.

 

[Moleculo]

A TNC is just a modem for RF. It lets your computer use the radio as the transmission medium. Most of the digital modes that you can use with your computer don't need a TNC; they just interface with your soundcard. The digital modes let you chat with other people same protocols on their computers. It's just like online chat, only you're doing over the air. You can also send & receive pictures, files, etc.

The TNC is really only needed for certain modes or protocols, or where you want the radio to be able to handle digital traffic in the absence of a computer. For example, some modes like Pactor are called ARQ modes. That means that the error correcting is handled every few packets, with the receiving radio sending acknowledgments or retry requests very quickly throughout the transmission of the message. Right now there aren't very good ways to handle this using just a soundcard. That's where the TNC or RF Modem comes in.

With APRS, you need a TNC built in to the radio if you want to be able to read the messages on the radio screen and also be able to transmit the messages. The alternative is to use a computer and TNC attached to the radio. You don't really need a TNC for the computer to do this, but the configuration becomes a little cumbersome.

 

[C2]

Well, you can use a computer soundcard as a TNC.