Amateur Packet Radio

So you may have heard about packet radio in the distant past, but what is it today?  Packet radio became a reality in the early 1980's when ASCII (American Standard Code for Information Interchange) was approved as a method for data transmission over the air.  It was in its prime until the 90's when the internet took over.

Yes packet radio is the basis for APRS (Automated Packet Reporting System) on 144.39 Mhz, but packet is more than just unconnected packets.  Packet can be connected packets finding their way around the world by a hierarchical method of location addressing.

The intricacies of packet are best explained by this series of documents written by WB9LOZ.

Packet is not dead, it is alive today and passing information for the National Traffic System, Bulletin Boards, and personal messages between hams.  Packet can get through when the internet can't.  Packet is error-free, it may have re-tries but when it does get through, the message crosscheck insures that the data is intact.

Look at all the packet activity around the world on the nodemap.  There are more than what are shown here.

http://nodemap.g8bpq.net:81

Packet operates primarily on RF via the 2 meter band for local hops, and 20 meters for longer hops.

• Typical frequencies are on FM 2 meter band: 144.93, 145.01, 145.03, 145.05, 145.07, 145.09 and 145.53 MHz running 1200 baud.

• HF BBS in North America, you can find the "Network 105" BBS on 14.105 MHz LSB running 300 baud.

• There are backbone links between BBS's on 220 and 440 Mhz as well, but most of the local activity for users is on 2 meters.

So how do you get in on this technology?  All you need is a 2 meter FM radio and some knowledge of where the packet activity is in your area.  You can use a SignalLink, or any sound card as a modem.  Sound card modem software packages are SoundModem and Direwolf.  You can use a Terminal Node Controller that was purchased at a local hamfest or fresh off the shelf of your amateur radio product dealer.  The favorite TNC is the Kantronics KPC-3.  This TNC contains the appropriate firmware to maintain a Bulletin Board System (BBS) within the TNC itself, requiring no external devices other than a computer with a terminal program to access the data over an RS-232 serial port.

What if you want more?  What if your QTH is the only one with access to the BBS backbone of the packet radio network?  In that case you may want to become a SYSOP (System Operator).  This is the next level of BBS system.  It can accept messages and traffic from BBS's via the Internet or from an RF source.  It can distribute the internet gathered bulletins and pass messages back through the BBS backbone.  In this case you want to look into BQP32.  Written by G8BPQ this fully featured software suit will enable your node to become a fully featured BBS net/rom.  And there are versions for Linux and Raspberry Pi as well.

If the documentation seems overwhelming, or unclear there is a shortcut for Linux users.  Run the bqp-config configuration software from AC0KQ.  Run it once, get the settings roughly the way you need, and then don't run it again.

Still confused, need it all step-by-step.  NL7OM has the guide for you.

Here is an excellent guide to each parameter in BPQ by AG6QO.

So after all that configuration you are ready to get online.  My node is CLYPA:N3FIX on 145.030 Mhz, part of the Underground Packet Network of Central Pennsylvania.  This node acts as a digipeater and serves to forward BBS messages and serve the South Central Susquehanna Valley from Cly, PA near 3 mile Island.  The antenna is a classic Ringo-Ranger fully restored and mounted on top of the roof fed by LMR-400 coax.  The rig is a simple 25 watt Azden PCS-4000 courtesy of KA3LJL.  The TNC is a PK-232 MBX running KISS mode operated by a first generation Raspberry Pi running PiLinBPQ software.

• N3FIX-1 is the BBS server
• N3FIX-2 is the CHAT application

 

The humble Ringo-Ranger

The humble CLYPA alias node in the basement running unattended.

K3CHB had a good idea to install the Raspberry Pi INSIDE the PK-232.  This is a pretty good idea, and I may try that sometime.