Ampersand-ASL: Installed and Working

Read Time: 5 minute(s)

I was curious about a fairly new AllStar project that doesn’t use Asterisk. (Both AllStarLink and HamVOIP use Asterisk.) The new project is called Ampersand-ASL by Bruce MacKinnon KC1FSZ. Find it on GitHub at https://github.com/Ampersand-ASL/amp-server/tree/main

To do this, you need an AllStarLink node number. I chose to extend one of my nodes with an NNX number, creating node 578499. I set my router to forward the UDP port I chose for this server to a Dell 3040.

Installing it was easy, and it was made easier because I cheated a little bit. How? By purchasing a Dell Wyse 3040 computer from AllScan.info. David NR9V did a great job of preparing the 3040 so that all I had to do was plug in a USB stick with Debian 13 and boot up. Debian installed painlessly and then I simply followed the most recent directions on GitHub for Ampersand-ASL.

For the microphone interface, I used a new AllScan UCI90 interface with included USB-C cable. I did not change any settings on the UCI90. It just worked, right out of the box.

The list of components are:

• Dell Wyse 3040 thin client mini computer and power adapter
• AllScan UCI90 microphone interface with a USB-C cable (comes with the UCI90)
• Kenwood K-1 speaker-mic

That’s it. This may be the simplest hardware package for an AllStarLink node ever.

Once Ampersand ASL (“Amp-ASL”) was installed, I needed to configure it. Below you see the Amp-ASL Server page as it was displayed on my computer. I set this up as AllStarLink node 578499. In this screenshot taken after I’ve configured and tested the Amp-ASL Server, I’ve connected ASL 578499 to my “node in the cloud” ASL 57945. This page is at 192.168.68.88:8080 on my LAN:

When you click the Configuration link on the Amp-ASL Server page, you get a screen that looks like the one below. (I’ve erased my password for obvious reasons.)

For the Audio Device, I clicked on the pulldown arrow and selected the only choice presented. I did not need to change the Receive Mixer from 0dB. The Enhanced Parrot at ASL 55553 reported audio was “pretty good” when I transmitted with the Receiver Mixer at 0dB. The package author notes that this terminology can be confusing, and explains it as follows:

The audio level that you are transmitting into the ASL network is controlled using the “Receive Mixer” level on the configuration screen. This is a bit confusing since the “Receive” in this context is from the perspective of the radio interface hardware.

Starting the server is easy from an SSH connection:

cd ~
cd amp
./amp-server

While I was working on the 3040 computer over SSH, I ran amp-server in a screen session:

cd ~
cd amp
screen ./amp-server

That way, I could continue working on the computer while amp-server continued to run. However, this does not persist when you power down and then boot up the machine. To make it persist, you install it as a service and tell it to run when the machine boots. The instructions for this are at the bottom of this page: https://github.com/Ampersand-ASL/amp-server/blob/main/docs/user.md. I tested this and it works.

If you are interested in a lot more detail (and it is actually pretty interesting!) about Amp-ASL, visit: https://mackinnon.info/ampersand/

That’s about it. This is a fairly simple looking setup and I’m sure it will continue to improve.

Does it work? The Enhanced Parrot says yes! I’m using a Kenwood KMC-45D K-1 speaker-mic for this test:

Amp-ASL also has a special parrot at node 61057 that supports 16 Kbps audio, but the great thing about this parrot is you get decibel values for your transmitted audio:

Why is 16K audio significant? Well, it’s not significant for typical communications, but where it will shine is in desktop-to-desktop digital communications via Amp-ASL:

The system supports a 16K audio mode that we’re calling “ASL-HD.” This may not be relevant for links between typical analog repeaters that operate with narrow audio bandwidths, but “pure digital” links (i.e. desktop-to-desktop) sound much better in 16K.

Is the Amp-ASL system ready for prime time? I think it is getting there. The package author notes some things are not yet implemented:

• DTMF pad
• CTCSS/PTT functionality
• Repeater functionality
• List of linked nodes for each node
• More status messages need to be shown on the main page

It’s exciting to see an AllStar system that does not use Asterisk PBX software for audio processing. This project is innovative and opens the door to more compact implementations. I’m looking forward to seeing how Amp-ASL evolves!

By the way, I also installed the UFW firewall and added a few rules to allow SSH and HTTP access. I also allowed the UDP port that I specified when I set up the node number at AllStarLink.org. That UDP port is also forwarded from my router to the IP address of the Dell 3040 computer.

Finally, I also took a look at the load on the system, using btop. The Amp-ASL Server is not pushing the Dell 3040 at all hard:

After posting this article, Bruce sent me instructions on updating to the latest version of Ampersand ASL Server. The updated interface looks nice:

And the audio test on the 16K parrot worked well: