Well before the likes of Meshtastic and Meshcore came about, radio amateurs were using packet radio to connect nodes to each other via RF links and communicating via the routes they established. That all started back in the 1980's and despite packet radio use reducing drastically, it is now seeing something of a resurgence. We thought if time to go back to the good ol' days, reminisce a little, all whilst looking to the future...
 |
| Our retro line-up for this series! |
Interestingly, there are a plethora of YouTube videos on how to setup modern software-based packet systems, but little on how to actually use packet radio. So, in keeping with our back to the future theme, we figured we'd ignore the software side of it and go back to using an old style TNC - the PacComm Tiny-2 Mk-2, in conjunction with a dual-band Kenwood TM-V7e radio.
This isn't going to be a how-to guide on setting up the TNC, but the series does hope to show you how to navigate your way around the packet radio network and show you the sort of things you might find / do.
For those that are interested, we used a 1997 PacComm Tiny-2 Mark 2 TNC (I mention this as the command set available and functionality is subtly different from the Mark 1!). This was connected via the data port that is available on the Kenwood TM-V7e and to a Samsung N150 notebook running Windows7 and PuTTY.
 |
| Setting up PuTTY to talk to the TNC |
The first thing to do was to set our callsign up in the TNC using the MYCALL command:
cmd:MYCALL G5JJ
Now, packet radio is one of those areas that is confusing, opaque, frustrating and yet somehow quite compelling... especially appealing to computer network nerds! With this in mind, the next thing was to find out if there was any local packet radio happening, otherwise our delve into the past wasn't going to last too long! One way to check is to look for packet radio 'blips' on an SDR and there are known frequencies to check:
- 144.800: APRS
- 144.950: Seems to have the most traffic locally for packet radio, but also 144.9375.
We are going to ignore APRS for now, although it is entirely possible to send packets to the APRS network and for information to show up on aprs.fi, it's also feasible to use packet radio on the satellites too - something that G7BEH has done in the past using the ISS as the repeater. Again, recently there seems to have been a resurgence in packet capable satellites, so we'll maybe take a look at that in a later article. But for now, back to 1997...
We weren't using SDR's back then so we needed to a way to monitor the frequency to find out what traffic was on there. For that we used various monitor commands, but even those can get confusing. Here's what worked for us:
MONITOR 3
MCOM OFF
MCON OFF
MALL ON
Listening in to 144.950 for a short while, we could start seeing traffic flowing between nodes on the network. This gave us a good idea of where to start, but before that just a quick observation... looking down the screenshot we can see stations beginning with GB7xxx and MB7xxx. Those starting with "MB" are gateways only and, perhaps counter-intuitively, do not have a mailbox, whereas those starting with "GB" are also gateways but do have a mailbox!
 |
| Screenshot showing the results of traffic monitoring |
In part 2 we will connect into one of those stations and start looking around.
No comments:
Post a Comment