A summary of requirements:
- Licensing: Technician - very minimal requirements
- Equipment: Transceiver, Terminal Node Controller and terminal
- Transceiver - traditionally a VHF/UHF FM radio
- Terminal Node Controller - Partly a modem, partly an AX.25 layer manager
- Terminal - Any serial terminal will do, but most likely you will use a personal computer
- A bulletin board system to connect with.
Let's break these down a bit.
You're in luck here as the technician class license is easy to obtain only requiring minimal study, no code, and learning the basic rules of how to transmit without going outside the allocated frequency privileges.
There are a growing number of ways to pass a digital message or two around, but the traditional meat and potatoes way for AX.25 packet is with a 2m or 440 FM transceiver. The audio connections marry with the modem IO of the terminal node controller.
Terminal Node Controller (TNC)
You're in luck here as well as in addition to a fairly large used market, new makes and models of packet ready modems are coming online. I think we have the APRS system to thank for these recent development efforts. Some TNCs have both the modem component along with the AX.25 management firmware. For these all you need is something that can connect to an EIA232 style serial port.
Another kind of TNC is the KISS (keep it simple) version that omits some or all of the AX.25 network firmware leaving a much simpler and much cheaper modem in place. There is still a serial port, but the expectation is a program running on the other end of that serial line will perform the necessary AX.25 network management features.
A modern approach is to skip the standalone TNC and connect the transceiver audio directly to a computer soundcard port. Numerous programs exist that will perform all packet functions (modem and AX.25) within the PC and make the resulting "terminal" text available on some TCP/IP port or virtual serial port. This is likely an excellent way to initially explore packet radio.
At the user end of the above, you have a simple text entry screen with responses typed on your display. What you actually type here is a learning exercise and a really good resource to learn the basics may be found on this very old, but nonetheless excellent resource...
Bulletin Board System (BBS)
Here is where things get a bit difficult. In the old days, numerous BBS systems were available for hams to connect with and leave messages to each other. Some are still around, but packet radio fell out of favor after excessive traffic proved too much for AX.25 and the relatively slow data speeds to handle with any practical utility. You may be in luck and have a local BBS you can connect with and I'm sure the sysop may well allow access for want of users.
Several of us in our area are in the planning stages of rolling out a BBS available on a variety of frequencies including HF (shortwave)...
Virginia Packet Network
We have not made it through a feasibility study yet, but the prepper community is one target "market" for such a system and your very question gives us hope.
Note that ham BBS users may interact with the typical BBS system entirely on the command line, sending, receiving and listing, BBS "mail" not unlike modern email concepts. There are also programs you can run on your local PC that will interact with the BBS behind the scenes, but organize the display and management of the messages on your machine much like a modern email program. Once such example is Outpost Packet Message Manager (PMM). I, for one, love the convenience of Outpost, but relish the fact the straight terminal interaction with the BBS is still possible if a terminal is all you have at the moment.
I will add that some of the more expensive standalone TNCs have BBS functionality built in or available as an option. PBBS is what I believe it is called. Storage is limited by the amount of memory space and we are talking about values under 100 kbytes or so. It is, however, an almost plug and play BBS that you and your friends can access and use to store messages.
A few good points to know include:
- A BBS is infrastructure and if the SHTF, there is no reason to believe
someone's BBS will still be there to serve users. The Virginia Packet Network is focusing a great deal on this important aspect, but it can be hard to predict the harsh circumstances of hard times.
- As stated above we have APRS to thank for a lot of the development of new AX.25 modem products. One thing to keep in mind is the data send and receive buffers are often quite small. APRS packets are short enough to survive this, but practical BBS usage with much larger packets may simply not work with modems designed only for APRS.
- BBS software is in, surprisingly, very active development. BPQ32 is one such example. Yes it is as quirky as the web site design makes it look. It works though. If you decide to try making your own BBS system, BPQ32 is probably the best way to go these days and it is available in both Windows and Linux packages... very cool.
Having a way to pass messages between each other in hard times is important. The fact BBS packet radio interactions are no longer very popular may, in fact, be a good thing since traffic to/from such systems may remain manageable. "Infrastructure" concerns aside, I think you are heading in a good direction. It is certainly worth a good long look. We certainly are.