So after reading Old School Packet Radio you might be wondering how we can use this antiquated piece of hardware for anything useful. Well it might surprise you to find out that the Ham radio packet network and APRS (Automatic Packet Rreporting System) are still using the same protocols today that they were back in the 80’s (for the most part at least).
The biggest problems using this old equipment nowadays seem to be just finding a way to talk over a serial port. Most computers don’t come with serial ports anymore, and most USB to Serial adapters are talking at squeaky little metro-sexual TTL (Transistor-Transistor Logic) voltage levels which are too quiet for our elderly TNC to understand. The PK232MBX wants to speak in “RS232 By God” 12 Volt serial levels, and most USB-Serial adapters just can’t scream loud enough to be heard. You’ll know it’s happening when you are receiving data from the TNC, but no matter how hard you mash the keys, the TNC seems to not be getting your commands. That’s because it is not. If you do happen find a USB adapter that speaks full strength RS232 levels, grab a sharpie and draw a HUGE smiley face on it so you don’t lose it. Otherwise, you need a serial PCI adapter in your computer, or a built in serial port.
It would be really easy for me to get wound up trying to write instructions for getting your TNC and computer talking to each other, but that’s not what we’re here for. So through the magic of the internet … SNAP! you magically have your TNC communicating with your computer in interfaced to your radio. You’re now ready to configure the TNC to act as your ambassador to packet radio universe.
Picture this; you worked and scrimped and saved to scrounge up enough money to finally buy yourself a PK232MBX. After all night wiring serial cables and fiddling with terminal program settings you finally get it talking. What does it have to say? What magic awaits you on the ether of packet radio? Well, this.
AEA PK-232M Data Controller
Copyright (C) 1986-1991 by
Advanced Electronic Applications, Inc.
Release 01.AUG.91
cmd:
Ohhh Kaaaay….. Ummmm. “Help?”
cmd:help
Help:
AMtor PAcket AScii
ARq Connect BAudot
AList Disconne MOrse
FEc MHeard DISPlay
AChg CStatus CALibrat
NAvtex SIgnal FAx TDm
CONVerse Trans
Xmit Rcve Lock
RESTART RESET
MDCheck TClear
cmd:
Welcome to the 80’s snowflake. When hardware came with instructions, but they were called “Operating Manuals” and they were 266 pages long. They came printed and bound in a gray plastic 3 ring binder that I wish I still had. There was even a rectangular window cut in the cover of the binder that showed the title page of the manual cover underneath. It was glorious!
The good news is that there are really only a few commands between you an Packet radio operation. Namely you need to tell your TNC who you are (MYCALL), what time it is (DAYTIME), how often to announce itself (BEACON), and a few other things that change the way your TNC behaves on air. Here is a list of my normal setup commands along with a little explaination:
- MYCALL AC0TG – That’s me! My callsign. I’m telling the TNC how it should identify itself to the rest of the world.
- MYMAIL AC0TG-1 – That’s my mailbox (the MBX portion of PK232MBX). If someone talked to AC0TG, they are talking to me sitting at my keyboard if I am there. If they connect to AC0TG-1 they are talking to the bulletin board system on my TNC. They can leave messages for me to get later.
- HBAUD 1200 – I’m telling the TNC to ‘speak’ 1200 baud on the radio
- BEACON EVERY 90 – tell the world that my station exists every 90 (times 10) seconds. Basically sound my barbaric YAWP from the rooftop every 15 minutes.
- BTEXT AC0TG-1/B Ken in Thornton, CO – Sets my BEACON message
- DAYTIME 191231163558 – That’s now. Format is YYMMDDHHmmSS. Yep, the year is only 2 digits, not Y2K compliant! This really isn’t needed, your TNC will happily work without knowing what time it is, it just can’t tall you when things happened.
- 8BITCONV ON – Should the TNC strip the bit 7 from incoming packets. It’s just needed to make things prettier
- DAYSTAMP ON – when you add a timestamp, include the date.
- MSTAMP ON – Add timestamps to all monitored packets.
- CONSTAMP ON – If someone connects to me, tell me when it happened.
- MAILDROP ON – Turn on my TNCs internal mailbox (BBS)
- USERS 3 – Max of 3 users can connect to me at the same time
- MDMON ON – if someone connects to my Mailbox, let me snoop on them.
- UNPROTO ID VIA AC0KQ – Send my beacons out using the AC0KQ as a digipeater so many more people hear me.
That’s really it. I have all these commands written into a little Linux bash script that sets them all for me at once. I can reset my PK232 to factory defaults and be back on the air in literally 30 seconds or less.
!/bin/bash
printf "MYC AC0TG\rMYMAIL AC0TG-1\rHBAUD 1200\rMDMON ON\rMSTAMP on\r" > /dev/ttyS4
printf "CONSTAMP ON\rDAdate +%y%m%d%H%M%S\rDAYS ON\r" > /dev/ttyS4
printf "BEACON EVERY 90\rBTEXT AC0TG-1/B Ken in Thornton, CO DM79\r" > /dev/ttyS4
printf "UNPROTO ID VIA AC0KQ\rMAILDROP ON\rUSERS 3\r" > /dev/ttyS4
So after all this, what do we have? Well assuming the radio is connected and tuned to 145.050 and working correctly, and you live anywhere there is still a few packet radio stations around; after a little while your radio should make this cool “BRAAAAAAPP!” sound and you should start seeing messages (Beacons or traffic) from other stations nearby. You’ll see things like:
01-Jan-19 17:37:37 W6OAV-6>AC0KQ-7*>N0HI-2>KB9KC-7>BEACON:
W6OAV-1/B, W6OAV-7/N 145.05mhz Centennial, CO
This just says that there is a guy out there (W6OAV in Centinial) that has a station and he relayed his BEACON through a few stations. Everybody else out there is hearing my station beaconing “AC0TG-1 Ken in Thornton, CO” every 15 minutes or so. This has all been greatly simplified, but it should get you on the air.