Radioless ASL Node: Putting it ALL Together

Now that my Motorola is the candidate for a UHF APRS node, I am going to construct my AllStar node to function as a personal, radioless node. Stick around for the final build!

What Happened?

So in a nutshell, I can't solder thin wire to SMD components to save my life. And I'm VERY tight on money at the moment - both things contributed to the cancellation of the city-wide AllStar node.

Not all hope was lost, and I actually enjoyed using ASL when I connected to my Pi via DVSwitch on my Android phone. In fact I tested it with a node all the way out in California at about 9pm at night, which was really fun! This led me to the thought that maybe I didn't need to connect to the AllStar network via RF. And indeed I didn't.

Turns out, some (and most) USB headsets have a built-in soundcard system that utilizes the CM108/119 soundcard architecture already! The VolDn key acts as PTT - perfect for getting on the air (or in this case, the web...).

Parts Needed

So in order to build this simple, dumbed-down version of an AllStar node, you'll need the following:

• Raspberry Pi compatible with ASL - I've decided to ditch HamVoIP in favor of ASL3 - best decision I ever made, as it has all the needed interfaces. HamVoIP is for advanced users in my opinion, and ASL3 is pretty straight-forward. I have a Pi 3B+ but I'd recommend a Pi 4 or Pi 5.

• MPOW 071 (or compatible) headset - This headset should be connected via USB. The MPOW 071 seems to be the best option for this build but I have seen other models used. To ensure this headset is compatible, run "lsusb" in a terminal while the headset is connected to the Pi. Keep a note of the vendor - it should have "C-Media" in the description if it has the correct chipset. If not, there might be a way you can make the included chipset in yours work flawlessly. It involves changing some .conf file(s). I'm assuming that headsets with mute buttons, volume up and volume down buttons work, but I'll purchase a $20 Amazon pair and find out!

• Power supply - Can be the included Pi AC adapter, but I've seen many hams who've built radioless nodes power theirs off of USB power packs, especially solar charged ones. This ensures that you can take your node anywhere! As long as it supplies at least 2A or more, it should work just fine!

That's basically all you need.

Overall, this should set you back less than $100, and if you don't have an HF rig this would be perfect to talk to someone across the world (although some may complain that it's cheating). 

Right now as I write this, I have an MPOW 071 headphone set on the way. I paid less than $20 including shipping, which was free. As mentioned above, I will most likely purchase another headphone brand and test to see if it works just as well, which I'm guessing it will.

By the way, I asked ChatGPT if it could make some sort of 3d-printed mount. Here's the result. This is scary good, because my node LOOKS EXACTLY LIKE THIS:

Included Features

When I originally ran my ASL node, I decided to install SkywarnPlus on it by Mason Nelson, N5LSN. SkywarnPlus is an awesome feature that any and all AllStar nodes can and should have. It provides real-time watches, warnings, and advisories issued from the National Weather Service's free-to-use API. You can set county codes, specific WWAs, and have a TTS voice read off alert details.

I'm also planning on getting this to work again with DVSwitch and iaxrpt. Both are free and are relatively easy to set up. Of course, when it comes time to enter your IP address make sure you use your public-facing one. And don't forget to port forward too - many remote access problems from both these apps arise from this problem.

Well here in the next week or so, dial in to AllStar node #61693 and give me a call! 

Proven Headsets that Work

Disregard for now but here are some that I know or think would work:

• CM108 Sound Fob (obviously...)

• MPOW 071 series (The OG-Known-To-Work)

• New Bee H368 (a review from Amazon claims that this contains a C-Media chip)

More to come maybe...

Tests and Conclusions

Last night I got my headset in the mail so I tested it on the parrot repeater node (55553) in Texas. The audio is a bit muffled, but I've found a way to get even louder volume if you're having issues, even if you max out the simpleusb menu to 999. Notoriously, MPOW 071 mics are very quiet, but here's a a little cheat I discovered.

You'll need to access the ALSA sound service. Or you can copy this command to your terminal:

amixer -c # sset 'Mic' ##%

Where # is the card number and ## is the percentage of volume assigned to the mic. Mine is set around 80% with the simpleusb TX audio menu option set to around 800. By default, ALSA is set to around 33 or 49% - waaaaay too quiet for our needs!

My headset works but I've noticed that wiggling around on the jack causes the audio to distort, go quiet, etc. So either I have a hardware issue (the jack isn't making good contact or the solder joints are cold) or it just needs a good spray down of some contact cleaner. Regardless, it works. In fact I checked in on a Seattle net around 10pm local with a good audio report. I also got a fair audio report from VK4NGA on the Texas parrot node too, so I know for sure it works!