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Hello, I'm Hibby MM0RFN and I have compiled this to the best of my ability.
I work on the Debian project and can be emailed via hibby at debian.org
I work on the Debian project and can be emailed via **hibby at debian.org**
The things I love include Scottish Consulate & 57North & Bikes & Hacking & Debian & Radio & Curling & 🏳️‍🌈 & 🦊
## Thanks
I owe a huge debt of gratitude to a number of people for keeping my enthusiasm and excitement for Amateur Radio, Packet Radio and Debian alive over the years. I can only encourage you, dear reader, to find your own tribe of inspiration:
**Iain Learmonth, MM0ROR** - irl brought me into the Debian project and fanned the flames of my enthusiasm early on, and it is entirely his fault I have this passion for free software and the work I do in Debian. We used to try to send each other packet data across a room and spent long days trying to understand why it didn't work, and these experiments have formed the foundation of my knowledge and experience. You have had more influence and impact than you know - thank you so very much for these gifts.
**Tom Jones, MM6IRQ** - Tom's consistent ability to challenge my knowledge and nurture my enthusiasm for something have always been invaluable. There are very few other people I would be so happy to spend long days sat together in silence working on equally stupid ventures - for this, and many other reasons, you are my dearest friend.
**Tom Fanning M0LTE** - Tom's continued enthusiasm and knowledge of packet radio has helped keep mine alive and developing during our time working on the UK Packet Radio Network project, and you've proved to be a great sounding board for when I've had a half baked idea that needs development. Your ability to get shit done and your depth of knowledge means that people really look up to you and respect what you have to say - more than you realise.
The rest of the [OARC](https://oarc.uk). Y'all are a consistently fun community to be part of, and have kept the flame of my radio hobby alive for many years now - thanks to Paul M0TZE for bringing me in many years ago, and reminding me consistently of that time I was drunk in a field trying to transmit out of band. There is an exciting get-up-and-do it vibe to our community, and it has successfully overcome my natural recitence to dive in without research more than once, resulting in wonderful results.
The HAK5 podcast for sparking the first flame and introducing me to APRS and amateur radio way back in 2005/6/7. I have fond memories of hanging out in irc, talking nonsense and taking my first steps into becoming who I am now.
Thanks to those who've come before and wrote the software that I've spent nearly 20 years playing with for fun. The trail you all blazed with your creativity, technical prowess and determination all those years ago has gived many of us years of fun challenges and built a foundation for the future of our hobby. The depth of your understanding and technical ability will never fail to boil my head. Particular thanks to N1URO (now SK), G4KLX, G8PZT and many more at [[insert copyright links for ax25 tools]] who I haven't interacted with directly.

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@ -6,13 +6,13 @@ In packet radio, we connect our computers together over the air to transmit data
### Equipment
You'll need a Radio, and a computer with a cable to connect them together. Sometimes these are easy to buy online, and the moreadventurous can make them. If you've done [FT-8](https://en.wikipedia.org/wiki/FT8) or another datamode, you might already have this cable.
You'll need a Radio and a computer with a cable to connect them together. Sometimes these are easy to buy online, and the more adventurous can make them. If you've done [FT-8](https://en.wikipedia.org/wiki/FT8) or another data mode, you might already have this cable.
Learn more about some Radio equipment [here](equipment/index.md).
### Modem
You'll need a modem of some variety. For more advanced users this of often a piece of hardware such as a [NinoTNC](modems/ninotnc.md), but as a beginner you're better suited to a piece of software such as [QtSoundModem](modems/qtsm.md). As the software costs nothing and takes no time to be delivered, it's quicker to get started with!
You'll need a modem of some variety. For more advanced users this of often a piece of hardware such as a [NinoTNC](modems/ninotnc.md), but as a beginner you're likely better served with a piece of software such as [QtSoundModem](modems/qtsm.md). As the software costs nothing and takes no time to be delivered, it's quicker to get started with! No lunch is free, however, so this simpler starting point brings with it more configuration complexity!
Learn more about modems [here](modems/index.md)
@ -22,7 +22,7 @@ You'll need a client of some form to be able to connect to the network. I would
### Addresses
Every station on the network has an address. The Government issued yours when you passed your ham exam (or if you've not sat it, they will do once you pass!). My station, as an example, is MM0RFN on the air.
Every station on the network has an address. The Government issued yours when you passed your ham exam (or if you've not sat it, they will do once you pass!) - it's simply your callsign. My station, as an example, is MM0RFN on the air.
Sometimes, when we want to offer a service from our computer, such as a messageboard or chatroom, we will add a number afterwards. We call this an SSID, a Service Set IDentifier. Due to the limitations of AX.25, we can have from number 1 to 15.
@ -30,7 +30,7 @@ If you want to connect to my messageboard, you can tell your client to connect s
SSIDs are not necessary - some stations have a frontend that will let you choose what service you want to use when you connect.
When you call your local node or a nearby station, it is most likely they will have an SSID and you will have to call that.
When you call your local node or a nearby station, it is most likely they will have an SSID that you'll need to use.
### Modes
@ -39,11 +39,13 @@ Similar to normal radio, we have different Modes too.
Instead of AM, FM, etc, we break to them down to 3 categories:
* Protocol: How our data is encoded
* Speed: How fast our data will travel (tied to bandwidth)
* Modulation: what manner of sound we generate to achieve communication.
* Speed: How fast our data will travel
* Modulation: what manner of sound we generate to achieve communication
Both stations must use the same protocol, speed and modulation to communicate on a shared frequency.
You can see a good table of Protocols, Speeds and Modulations at [NinoTNC](../modems/ninotnc/#mode-switch) once you've digested the below and feel brave!
#### Protocol
We use two main protocols: AX.25 (legacy) and IL2P (modern).
@ -58,35 +60,37 @@ Learn more [here](detail/ax25.md).
##### IL2P
IL2P, the 'Improved Layer 2 Protocol' is by Nino KK4HEJ and is an evolution of AX.25. It includes nice things such as error correction of data and allows for, theoretically, more reliable communications but isn't compatible with AX.25.
IL2P, the 'Improved Layer 2 Protocol' is by Nino KK4HEJ and is an evolution of AX.25. It includes nice things such as error correction of data and allows for, theoretically, more reliable communications but isn't compatible with AX.25 on the air.
There are a number of varieties of IL2P in the wild too - learn more [here](detail/il2p.md).
#### Speeds
We often use '1200', '1200bd' or similar as shorthand for how fast our data is sending and received. The 'bd' is baud, or the number of symbols a second. For most of our communications, 1 baud is equivalent to 1 bit per second.
We often use '1200', '1200bd' or similar as shorthand for how fast our data is sending and received. The 'bd' is baud, or the number of 'symbols' transmitted a second. For most of our communications, 1 baud is equivalent to 1 bit per second, however more exotic modulation can transmit more than one symbol at a time, buying us more speed!
We 3 broad speed categories at the moment:
* 300bd - used on HF.
* 1200bd - used on VHF
* 9600bd - used on UHF and beyond
* Low - 300bd - used on HF
* Medium - 1200bd - used on VHF
* High - 9600bd - used on UHF and beyond
Nothing comes for free, and speed is normally proportional to your channel bandwidth. 300bd fits into quite a narrow space, 5-600Hz, which is why we use it on HF. 1200bd and other medium speed up to and including 4800bd are used in 12.5kHz FM channels, so appear on VHF and UHF. 9600bd and faster need 25kHz FM and higher channels.
#### Modulation
Modulation is a little more complicated than the others as there are many ways to modulate a signal!
If you've played with datamodes on a radio already, you will have a reasonable feeling for this already.
If you've played with data modes on a radio already, you will have a reasonable feeling for this.
The key modulations we use are:
**AFSK**
Audio Frequncy Shift Keying - Multiple audible tones. This is commonly found on VHF, FM 1200bd links.
Audio Frequncy Shift Keying - Multiple audible tones. This is commonly found on VHF, FM 1200bd links. Classic bleeps and bloops that have been heard on our frequencies for decades. Tune to 144.800MHz to get a flavour from the APRS network.
**FSK**
Frequency Shift Keying - Multiple tones, not necessarily audible. Commonly found on UHF, FM 9600bd links.
Frequency Shift Keying - Multiple tones, not necessarily audible. Commonly found on UHF, FM 9600bd links. This sounds quite like white noise and can be difficut to differentiate from unsquelched audio.
**PSK**
@ -98,7 +102,7 @@ Find out your local packet radio frequency first, and tune your radio to see if
If you're in the UK, this will be listed at [ukpacketradio.network](https://nodes.ukpacketradio.network/packet-network-map.html) or [UKRepeater](https://ukrepeater.net/packetlist.html).
If information is available online, also take note of the details of the mode as this will come in handy setting up your modem
If information is available online, also take note of the details of the mode as this will come in handy setting up your modem.
## Software Set Up
@ -134,8 +138,36 @@ Decoded data shall look like:
## Connect
Press Connect and select 'xxx'
Press Connect and enter the callsign & SSID you are trying to connect to, for example GB7HIB-7 if you're connecting to my node.
You should be presented with some choices in the bottom pane.
You should be presented with some choices in the bottom pane - BBS, Links, Info etc. If not, type `?` in the bottom text box, hit enter and see what the remote system returns with.
Congratulations, you are on the air!
Not seeing anything in the monitor pane? Time to get debugging!
## Debugging
This is where most of my time is spent when setting up packet radio stuff. In my opinion, it's where the real learning happens - you need to get your hands dirty with your radio, with your modem, with linux and try to retain your sanity at the same time.
Don't worry - there is always something you've forgotten to do, or think you've looked at and haven't. We all have that feeling. Sometimes I keep a note of what I've done and what I've looked at to avoid replication of work, or so I can note what I *have* changed and what I might need to replicate.
### Debugging Checklist
Learn more about debugging:
* [Your Radio](../modems/qtsm/#check-the-radio)
* [QtSoundModem](../modems/qtsm/#check-the-audio-coming-in-is-at-the-right-volume)
### Ask for Help!
It is easy to feel overwhelmed and alone as you struggle through debugging your system. Feel free to ask the community for help! No question is stupid, and we all started knowing nothing about this. Everyone is excited to have new stations and nodes to connect to, so will be thrilled to offer some form of pointer, assistance, input or advice. Please note, advice is a form of nostalgia: dispensing it is a way of fishing the past from the disposal, wiping it off, painting over the ugly parts and recycling it for more than it's worth.
There are a few great sources of assistance, some will be faster than others to get responses from:
* General help and chatter on all things packet: [Online Amateur Radio Club Discord](https://oarc.uk)
* UK Packet Radio Users: [uk packet radio mailing list](https://groups.io/g/ukpacketradio/)
* QtTermTCP and QtSoundModem help: [bpq32 mailing list](https://groups.io/g/bpq32/)
* NinoTNC: [NinoTNC Mailing List](https://groups.io/g/ninotnc/)
* My Inbox - see the [about page](about.md). I'll be thrilled if you get stuck and sent me an email saying you'd tried this and nothing worked!

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@ -30,8 +30,8 @@ If you don't want to spend a lot of money to dip your toe in, you don't have to.
Have a look to see if you have a [proven radio](equipment/radios.md) and install [QtSoundModem](modems/qtsm.md) and [QtTermTCP](clients/qtttcp.md) to access someone else's node.
I'd recommend trying 1200bd on VHF or UHF first, but slower modes on HF are perfectly do-able as well if you're on an island or stuck in a ditch,
I'd recommend trying 1200bd on VHF or UHF first, but slower modes on HF are perfectly do-able as well if you're on an island or stuck in a ditch.
Take a look at the [beginner's guide](beginners-guide.md) to see more detail about how to get started with this.
Take a look at the [beginner's guide](beginners-guide.md) to see more detail about how to get started.

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@ -50,11 +50,20 @@ Superseded (but still supported) modes:
| 1100 | 300 | 300 | AFSK | AX.25 | 300 AFSK IL2P | SSB | 500Hz | Backwards compatibility with legacy HF packet modems. Modulation invented c. 1962! |
| 1101 | 300 | 300 | AFSK | IL2P | 300 AFSK IL2P+CRC | SSB | 500Hz | IL2P improvement of AFSK 300 baud AX.25. |
Prefer:
Our order of preference for modes at UKPR are:
* QPSK > BPSK > DPSK > AFSK
* IL2P+CRC > IL2P > IL2P > AX.25
* SSB > FM
Why? Simply put, see the below three statements but tread carefully. Not all things are equal, and not all rigs are capable of 'optimum' performance. Perfection is the enemy of good enough, so please endeavour to get something working, not something perfect.
Modulation: These modes offer increasing bandwidth efficiency, with QPSK being our over SSB being our preferred - AFSK over FM is the least efficient mode.
Protocol: IL2P+CRC is the most resilent mode against corruption or data loss as it transits the air, with AX.25 being unprotected against this.
Mode: SSB is preferred as the channels are narrower and allow for more flexibility - tigher filtering and better amplification per hz. FM is good enough, however.
### Signals Switch
#### Switch 1 - Transmit audio range selection - DATA/MIC
@ -76,3 +85,43 @@ Leave in the off / down / AC position unless you have a rare case where having t
#### Switch 4 - External carrier detect - EN/CD
Leave in the off / down / CD position unless you want to provide external transmit inhibit using pin 2 of the DB9 connector.
## Debugging Strategies
Link not working as well as you want? Can your friends not hear you? Can you not hear them? Let's take it back to basics and see if we can find the problem.
Let's strip the complete system back. Make sure that BPQ or other node software is stopped - it's going to want to take over the modem and that'll get in the way. This will be easiest if you can connect to your TNC with a client such as QtTermTCP that offers both monitor *and* interactive panes. If you're running the [linux stack](../config/linux.md), you can run `sudo axlisten -ac` to see the data decoded by your modem.
### No Received Signal
Not seeing anything in the monitor? We need to think about two things here: Is the modem receiving signals from the radio, and is the computer receiving signals from the modem. Let's eliminate each issue one step at a time.
#### Radio -> Modem Fault
First off, [check the radio](../qtsm/#check-the-radio) and [check the cable](../qtsm/#check-the-cable). Check if the radio is set up for outputting audio through the accessory socket you're using, and it's in the correct mode (1200bd vs 9600bd - check your manual). A good test here is can you *hear* the signal you want to decode? If you can hear it, we need to find out why your modem can't. As the faster modes sound quite close to white noise, this doesn't always hold true, but it's a least a starter. Perhaps combine eyes and ears and watch the S-meter too!
I often confuse the 9600bd and 1200bd lines on my interface cable - have a look to see if you've done the same. More often than not, this has melted my head during cable construction, or I'm using the cable for my [UHF Radio](../equipment/ft-7900.md) on my [HF Radio](../equipment/ft-891.md).
Next up: is your modem in the right mode? Look online at either the node's website or [UKPRN Website](https://ukpacketradio.network) for hints and clues or [ask questions](../../beginners-guide/#ask-for-help) of your peers - we're here to help.
Finally - is your radio outputting enough audio? Is it too much audio? Look at the LEDs on your NinoTNC. Here is a guideline of how to read them:
#### Modem -> Computer Fault
Is your modem decoding a signal?
You can tell by the RX DCD / Green LED lighting when a packet is successfully received & decoded.
It's being powered, and that's presumably from the computer USB port, but maybe it's not connected properly.
Check if it is a serial device: run `ls /dev | grep ttyACM`, unplug the modem and run the command again. If there's a difference, when you plug it back in and rerun the command (for a third time, yes!) you should see a new device appear, and appear similar to below:
```
hibby@GB7HIB:~ $ ls /dev | grep ttyACM
ttyACM0
```
We've now identified your modem's device and we know it is appearing on your computer. If it isn't, then start by trying a new USB cable.
An alternative command to look at running before and after disconnect is `sudo dmesg` - this should tell you if the kernel has detected your device disappearing and reappearing.

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#QtSoundModem
hi
# QtSoundModem
QtSoundModem is a soundmodem with a GUI written by John Wiseman G8BPQ. It is a fork of UZ7HO Soundmodem.
It has some compelling features - not only does it natively understand IL2P at a number of different baud and bitrates and modulations, it supports multiple modems, each with a different KISS interface. This allows for up to 4 ports with different speeds, protocols and modes in the same channel - a fantastic thing to explore on HF.
## Software Set Up
### Installation
If you're using Debian, Ubuntu or a Raspberry Pi it will be easiest if you install [hibby's repo](repo.md).
Once you have done that you can install the prerequisites:
`sudo apt install qtsoundmodem`
## Configuation
Configuration is done through the menu system.
### Modem Configuration
## Debugging Strategies
First off, make sure you have your terminal open and at the bottom right it says 'KISS Connected' or 'AGW Connected' depending on how you've configured your interface from your soundmodem to terminal.
### Receive Check
Sense check: are you hearing the remote station coming in to your radio? Have you heard it in the past?
#### Check the radio
Let's work out what's changed if you've heard the remote station in the past.
* Are you on the right frequency?
* Are they experiencing a temporary outage / expected break?
* Is your antenna OK?
* Is it in the same place?
* Is it plugged in?
* Is the radio even on?
* Is everything real or am I just living in a simulation? ...Wrong list of questions
#### Check the cable
Is the cable connected to both the radio and the computer -
* Are there any obvious breaks in the cable?
* Are the jacks at the computer end plugged in to the correct sockets?
* Maybe just reseat the cable to check it's plugged in correctly.
#### Check the audio coming in is at the right volume
!!! note
This shall use the Pulse Audio Volume Control program, which is an invaluable friend in wading through Linux audio problems. If it's not obvious where this is in your application launcher, you can open a terminal and type `pavucontrol`. If you don't have it, you should `sudo apt install pavucontrol`.
Open the input devices tab - does the VU bar of your soundcard show any activity? In the below screengrab, I have a little audio that is probably just background coming to my Built in soundcard. In many scenarios you'll be using a USB or external soundcard, it might be called a CM108 or similar - be sure you're looking at the right device. Low to no audio as I am showing indicates an issue or an error in the cable. It also might indicate your radio is squelched, be sure to check your squelch is off if possible.
!!! note
If you have no audio coming in and your radio is unsquelched, double check your cable is ok (maybe with a volt meter, or remove and reconnect the ends). Check you are looking at the right soundcard, and check each jack is going to the correct socket on the soundcard.
If you receive a packet and the VU bar goes all the way or is very high, your incoming audio is too high - bring down that slider below the VU bar. If your incoming audio is too high, it might be distorting as the computer digitises it. Having it peak at half way should be more than enough volume.
![receive audio window](static/img/input_devices.png)
This resolves to the following questions:
* Is the computer receiving audio?
* Is the received audio too high?
#### Check the audio coming in is going to the right application
As in the above segment, open Pulse Audio Volume Control but this time go to the 'Recording' Tab. You should see an entry for QtSoundModem, or Direwolf if that is your poison of choice!
The VU bar should show activity when a packet is received, just like the one in the Input Devices Tab. If not, you may need to change the device the audio is coming from - there will be a dropdown that lists all your computer's audio inputs and you can select. Again, there is a slider here for volume control - the effects of this are additional to that of the Input Tab, so dropping audio by 6dB in both locations will create a total drop of 12dB. Due to this, I generally recommend leaving it at 100% / 0dB and only modifying the Input Device slider.
[insert image]
If you have sorted routing, wait for more packet traffic to see if anything appears in your Terminal monitor pane.
To understand if QtSoundModem is receiving audio, you can look in the waterfall window within the application:
[insert image]
This resolves to the questions:
* Is the application receiving audio?
* Is the correct soundcard selected
* Is the application audio too high or too low?
### Transmit Audio
#### Check the generated audio is going to the right soundcard
Open Pulse Audio Volume Control but this time go to the 'Playback' Tab. You should see an entry for QtSoundModem, or Direwolf if that is your poison of choice!
If your modem is not receiving audio, check in the configuration to be sure it is outputting audio to 'Pulse'. In QtSoundModem, this will look as below:
[insert image]
The VU bar should show activity when a packet is transmitted, just like the one in the Input Devices Tab. If not, you may need to change the application volume, and double check the soundcard the application is being sent to. Tere will be a dropdown that lists all your computer's audio inputs and you can select. Again, there is a slider here for volume control - the effects of this are additional to that of the Output Devices Tab, so dropping audio by 6dB in both locations will create a total drop of 12dB. Due to this, I generally recommend leaving it at 100% / 0dB and only modifying the Output Devices slider.
[insert image]
If you have sorted routing, generate more packet traffic to see if anything appears in your Terminal monitor pane.
To understand if QtSoundModem is transmitting audio, you can look in the waterfall window within the application:
[insert image]
This resolves to the questions:
* Is the application registered in pulseaudio?
* Is the correct soundcard selected
* Is the application audio too high or too low?
#### Check the audio leaving is at the right volume
!!! note
This shall use the Pulse Audio Volume Control program, which is an invaluable friend in wading through Linux audio problems. If it's not obvious where this is in your application launcher, you can open a terminal and type `pavucontrol`. If you don't have it, you should `sudo apt install pavucontrol`.
Open the input devices tab - does the VU bar of your soundcard show any activity? In the below screengrab, I have a little audio that is probably just background coming to my Built in soundcard. In many scenarios you'll be using a USB or external soundcard, it might be called a CM108 or similar - be sure you're looking at the right device. Low to no audio as I am showing indicates an issue or an error in the cable. It also might indicate your radio is squelched, be sure to check your squelch is off if possible.
!!! note
If you have no audio coming in and your radio is unsquelched, double check your cable is ok (maybe with a volt meter, or remove and reconnect the ends). Check you are looking at the right soundcard, and check each jack is going to the correct socket on the soundcard.
If you receive a packet and the VU bar goes all the way or is very high, your incoming audio is too high - bring down that slider below the VU bar. If your incoming audio is too high, it might be distorting as the computer digitises it. Having it peak at half way should be more than enough volume.
![receive audio window](static/img/input_devices.png)
This resolves to the following questions:
* Is the computer receiving audio?
* Is the received audio too high?

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font: false
markdown_extensions:
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