TwinsLAN got its start with the growing interest in packet radio in the early 1980s. Packet radio is a means of connecting amateur radio operators together using techniques that aren't much different than the way two individuals can connect their computers together and communicate with each other using a telephone modem or Internet connection. The big difference is that instead of using a telephone connection, amateurs use wireless radio connections.
A typical packet radio setup consists of a computer or terminal, a terminal node controller (TNC), amateur radio transmitting and receiving equipment for VHF (very high frequencies -- around 145 MHz), and an antenna. The TNC works a lot like a telephone modem does but it also manages the flow of data between the computer and the radio-based network. Some TNCs even incorporate mailboxes so that amateurs can send and receive mail messages (wireless e-mail).
If you have a scanner or other receiver capable of receiving VHF FM (frequency modulation) signals you can listen to the sound of packet radio by tuning to frequencies like 145.01, 145.67, or 144.39 MHz.
There are not many companies in 2015 who still manufacture and sell packet TNCs. With faster computers we now have sound-card software that does the same decode and encode functions that the TNC used to do, and most of the software is FREE. If you are interested, start your search with any of these keywords: DireWolf, UZ7HO, AGWPE. There are versions of this and similar software that will run on most platforms; desktop computer, laptop, tablet, and even cell phones. If the device has a built-in microphone, you can probably test reception just by putting the radio speaker near the device. If you have a general interest in digital modes, you should extend your search with a more generic search for "sound card software". The web page in the following link is pretty old but does provide a look at sound-card software development since the days of 150MHz Pentium CPUs. Amateur Radio Soundblaster Software Collection.
Tuscon Amateur Packet Radio (TAPR) hosts an Introduction to Packet Radio prepared by Greg Jones, WD5IVD.
For a good tutorial on packet radio click on Introduction to Packet Radio by Larry Kenney WB9LOZ
Lots of really good information regarding packet radio, PSK31, and other digital modes as well as radio-to-tnc and radio-to-computer connection information can be found by clicking on www.packetradio.com. Many thanks to Buck Rogers, K4ABT, for putting all that info on his site. You can use the info to "roll-you-own" or buy an interface from Buxcomm or any of the other ham radio manufacturers....
Many years ago TwinsLAN obtained copies of the NEDA 1994 Annual to be distributed at one of our
local packet radio conferences. I believe the NEDA group had closed down and was giving away old copies
of the annual. We handed them out at the conference and years later I scanned my copy into a PDF file.
I've never seen the document anywhere else and decied to make it available on this site for others to
use. Note, I'm not the copyright owner and if they request, I'll take it down again. But it is excellent
informaion for new and old packet users to have. This link will attempt to open the 37MB PDF file.
You should right-click and Save the link instead. This page last updated 08.14.2015 comments to twinslan@twinslan.org