Table of Contents
Building a packet user station
A “User” is someone that temporarily connects to their local packet node, interacts with the node to send mail for example, and then disconnects. When they're not using the radio for packet they might use it for something else.
Radio
To start using packet you will need an FM radio of some description. Most user traffic will probably be on the 2 metre band.
We've started compiling a list of suitable radios and instructions to interface them here - packet:transceivers
Note unfortunately that due to poor turnaround times, cheaper radios such as Baofengs and the like probably won't be suitable, however suitable radios can be picked up at rallies for as little as £5. They *might* work, but would certainly be discouraged for anything other than bench testing and experimentation.
Software
Windows
If you're using a KISS TNC such as the NinoTNC, you will need a Packet Terminal. See QtTermTCP or xrouter in KISS terminal mode.
If you're using a Sound Interface, you will need a Software Modem. See QtSoundModem as well as a Packet Terminal, as above.
Linux
If you're using a KISS TNC such as the NinoTNC, you will need a Packet Terminal. See QtTermTCP or xrouter in KISS terminal mode
Frequencies
You'll generally find packet nodes on the following frequencies. Note that whilst the Bandwidth is set, the usage may vary.
VHF / 2m
The default “legacy” mode is 1200 baud standard AX.25, though newer modes, modulations and encodings are starting to appear, offering more resilience and throughput.
| Frequency | Bandwidth |
| 144.925 | 12.5 |
| 144.9375 | 12.5 |
| 144.950 | 12.5 |
UHF / 70cm
25kHz channels, might be using 9600bps or more. Nodes may also be using IL2P (Improved Layer 2 Protocol) and FX.25 (AX.25 + Forward Error Correction)
| Frequency | Bandwidth | Usage |
| 430.200 | 25 | Forwarding |
| 430.225 | 25 | Forwarding |
| 432.625 | 25 | User Access |
| 432.650 | 25 | User Access |
| 432.675 | 25 | User Access |
| 433.625 | 25 | User Access |
| 439.900 | 12.5 | Forwarding |
| 439.925 | 25 (with overlap to lower adjacent channel) | Forwarding |
| 439.950 | 25 (with overlap to upper adjacent channel) | Forwarding |
VHF / 4m
Legacy channels, no new applications can be granted on 4m.
| Frequency |
| 70.325 |
| 70.4875 |
VHF / 6m
| Frequency | Bandwidth |
| 50.650 | 10 kHz |
| 50.660 | 10 kHz |
Exotic stuff
Not packet radio, but worth a mention:
- 144.8000 APRS
- 433.8000 APRS where 144.8000 MHz can’t be used e.g. Within 50km of TA012869
- 439.9125 LORA APRS Low Power only no amplifiers permitted
- 439.9875 Pagers
- 5675.0000 Mesh networking - using CE Licensed Exempt Equipment does not require frequency clearance
Reference: https://ukrepeater.net/doc_files/PacketRadioFrequencies.pdf