BBS Packet Radio

 Okay, so my AllStar node was a bit too...ambitious. Therefore, Project AllStar has been cancelled :( I might make a personal radio-less AllStar node just for me.

That's okay, though, because I have a better and easier project that even YOU can do! And this should still benefit my community too!

The NEW Plan

Unfortunately, the time it would take me to put together an AllStar node has been eaten up, and as much as I'd like to put one up for the community to use, I found that the one thing holding me back was the CM108 soundcard. SMD soldering just isn't for me, and I had to go through three or four of these to figure that out :(

Luckily, we aren't defeated yet. After contemplating what to do with a 70cm transceiver and a Raspberry Pi (a Pi Zero for that matter!), the thought of APRS and packet radio crossed my mind. And I'm going to stick to that idea.

Now I know what you're thinking - APRS is VHF only, right? Think again - many large cities with heavy ham populations use UHF as a secondary means of APRS and packet, and despite 9600 baud being the standard, 1200 baud is not unheard of on 70cm. And BBS packet, also more common on HF and VHF, is best suited for UHF since we have over 30MHz of bandwidth in this allocated band!

In an earlier post I wrote about APRS on 70cm. There are various frequencies, but one frequency in general was suggested - 444.925MHz. Looking back on this, while this might work, 444.925 is where most 9600 baud packets run. I recently discovered that another ham somewhere runs P25 packets on this frequency too. Somewhere in 430MHz land would be a better option, ie, 432.930 for example.

Hardware and Software

Luckily for us, this setup will not require any CM108 modification, at least I wouldn't recommend it for a starter.

To get started, here's what we'll need for hardware:

• A capable VHF or UHF transceiver - The Motorola SM50 will suffice perfectly for this. If you are on a budget, look for second hand transceivers or business band radios such as the SM50 or the GM300. Both models will work sufficiently
• A Raspberry Pi computer - I will be using the Pi Zero that I had from the digipeater project I abandoned a while ago. It should work just fine for what we need.
• A sound card interface - one example is an Easy Digi interface sold by KF5INZ on eBay. This board worked great for my TS-660 and will interface with almost every radio you've got
• An antenna - I would advise you to construct a 1/4-wave ground plane vertical. It would only be about 6.5 inches tall and wide. Place it about 20 to 30 feet in the air - this should work for great transmission and reception

For software, we need to run the following:

• OS - We'll need to run the Raspberry Pi OS, Raspbian. For space conservation, you can run the Pi headless so you'll only need to SSH into the Pi for maintenance
• LinBPQ - This is software that I'm new to. We'll use this for the BBS side of things
• Direwolf - The one and only amazing soundcard TNC software ever!
• Python script - Stay tuned...

Dustin, KM4MKB, has an excellent write-up on his page that details the entirety of setting up a packet node on a Raspberry Pi. Check it out here: https://themodernham.com/packet-radio-101-the-ultimate-guide/#bbs. Dustin is a really cool guy and has even shown an old Commodore computer connecting to the 14.105 LSB packet network!

The plan will be broken down as follows:

Phase I: APRS Functionality

While UHF doesn't have a dedicated APRS frequency, this will be a way to test it. The node will first have Direwolf installed as an APRS digipeater and iGate. Data transmission and reception

Functionality will work just the same as a VHF node - set your APRS settings to 1200 baud and send a packet on the set UHF frequency. Just like that. That's all there is to it. It's APRS but on UHF.

Phase II: BBS Functionality

When APRS testing is fully finished and is deemed successful, the most logical step ahead would be to install LinBPQ. This together with Direwolf will form the main hub for Maryville's own RF BBS network. Here, hams can post messages, information, and just about anything you'd find on an online BBS system. This BBS should be integrated so that RF users can post their information to both RF channels and online internet channels. Some hams customize their nodes to have text-based games available to play. Sounds like a cool idea!

Phase III: National Weather Service Alert Packets

This will more than likely take the form of a Python script, which will be sent to Direwolf to transmit over the airwaves. This will be an advanced topic, so it will take some time to fully develop and implement. The script will scrape information from the NWS's free API hosted online to collect severe weather watches, warnings and advisories. Please note that this does NOT take place of reliable sources such as the National Weather Service transmitter here in Maryville (KZZ37) or other media outlets. In times of severe weather, this functionality will add to the usefulness of amateur radio and packet networks to help spread weather awareness.

I won't go into too much detail right now as I've just conceptualized the idea. For now, stay tuned for an update where I will hopefully create a write-up about how you can get started! I hope I can bring 1200 baud APRS to UHF!!!