Lost in Transit

So far, my hit ratio for making a successful Winlink connection over HF is 1 out of 20. My antenna just sucks that much, and my radio keeps overheating and turning off the output, and QRM/QRN causes any ongoing connections to fail. And then there’s the difficulty of burning an RMS node by failing the connection, locking it up, and leaving it offline during the timeout before I can try reaching it again.

Radio is hard.

Unfortunately, I must rely on the nearby W3MRC RMS node on VHF to transfer mail via packet. I mean, it’s rock-solid, but it presumes that it’ll be online and powered if all of the Austin area loses power.

I’ll get better. Hopefully.

Winlink 2000 – Email on the Wind

Since I have my ham rig already set up for soundcard modes, I decided to give WinLink 2000 a try. WL2K is an email-over-the-air transport system that can take advantage of many modulation modes and frequencies, and allows a remote station with no Internet access to send and receive email messages complete with attachments. It’s useful for ship/boat stations, emergency communications during disasters, mobile/roving stations, camping/hiking stations, as well as a great thing you can do to get better at long-distance digital modes for fun and practice.

There’s a moderate amount of work that needs to happen up-front in order to use it. The Winlink service requires a valid amateur radio license from your country’s licensing authority. You will need to install some client application in order to compose/read mails and orchestrate communications. Once you sign up and make your first connection to the Winlink system, you will receive an email with your on-air password, which is then required to make subsequent connections. Your email address will be <callsign>@winlink.org and your inbound messages (to you) are filtered by a whitelist that is fairly restrictive. You can edit your whitelist on the Winlink web portal if you’re connected to the Internet, but otherwise any email address that you send to through the system will get added to the whitelist automatically; all other inbound mail is rejected.

On my home workstation, I installed and configured Winlink Express (published by the Winlink group). Winlink Express requests that you install the VOACAP (published by the Voice of America) propagation estimation software if you want to use its automatic link quality estimates. You’ll also need to install whatever software will be the modem between Winlink and your soundcard/radio (I used Direwolf in this situation).

The system can use several modes. The first, and simplest, is to use a basic telnet connection on an Internet-connected workstation to transfer messages. Your client software talks directly to the Winlink servers via the Internet. This is how I set up my account and got the basics worked out.

Another mode is Packet, which is your basic AX.25 packet radio mode, either 1200 or 9600 baud, “connected mode”. This is primarily used on VHF/UHF frequencies. If you don’t have a hardware TNC (Terminal Node Controller) that runs in Packet KISS mode, you can definitely use the Direwolf software TNC and tell Winlink to use it at a local network address and port instead of a hardware TNC at the other end of a serial connection. Direwolf requires some configuration from defaults to use your audio device. This is a good exercise to help you learn how to stitch multiple software components together to perform the work.

The third mode is Pactor, and is the mode of choice for anyone who happens to own an external Pactor TNC. This is a high-efficiency mode with extra error correction, signal processing, and high bandwidth (for MARS bands or if the FCC allows during disasters), but the external modems are expensive and outside the budget of the casual ham.

The built-in mode is Winmor (published by the Winlink software team). It is fairly robust and has a lot of handshaking and error correction, and the Winmor software TNC runs in a graphical dialog window to show you the signal quality, current action, and status of the transfer. Winmor uses QAM (Quadrature Amplitude Modulation) at certain times of the conversation with various constellation densities and bits-per-second speeds to fit what’s best for the HF link condition.

Winlink supports many more modes that I haven’t experimented with yet.

The Winlink system relies on a worldwide group of volunteers who run stations that listen on a published list of frequencies for remote stations that wish to connect. They will rotate through their frequencies until they hear a request. They then do a song and dance with the remote, and forward any mail between the Internet and the remote station. It is essential that you download the latest published list of RMS stations before you go offline. You can also request the latest list over the radio, but you’ll need to know at least one station you can reach for that to work.

Aside: you can also request help files, propagation reports, weather reports, etc., automatically with a click with Winlink Express; the Winlink base station will provide a copy on connection.

One thing that tripped me was the option to connect to a Winlink station versus connecting to a “radio-only” system. Winlink architecture allows stations to connect radio-only or P2P, allowing them to shuffle email around without an Internet connection. My assumption is that if a radio-only station gets a message and accepts it, it will use the next available time slot to start up an HF link to the next reliable station and pass it off until it eventually gets to where it needs to be. Not quite.

On the times I tried to connect to a station to transfer, it got through the handshake, my client saw that the outbound mail I had wasn’t destined for that host, and both sides closed the connection without transferring anything. In that situation, I should’ve used “Connect to Winlink” instead of “Connect to Radio Only”. But OK. Lesson learned.

I was highly successful with Packet, because there’s a station W3MRC here in Austin which is a gateway. I was able to transfer mail at less than 10W with a 2m antenna. However, transferring on the HF bands is significantly more difficult. The concerns with Winlink on HF are the same as any other HF mode: propagation is important, and so is your radio, antenna, feedline, etc. If they can’t hear you in the noise, you’re gonna have a hard time.

So the software will show you a list of stations (a “channel list”) sorted by estimated link quality. Your best bet is to find something with a high estimate. But keep in mind the frequency you’re using, the time of day, and the skip zone (ionosonde data is useful here). It’s no good trying a station 500km away if you’re on 40m at night and your skip zone is 1500km. I tried to reach stations in Ohio, California, Baja Mexico, Florida, from my Texas apartment on 40m, but my crappy dipole just couldn’t get enough energy into the atmosphere for anyone to hear me. So my best success was to reach station K0SI in Missouri (which is in the skip zone, so I dunno about that), which heard me well enough, even with the fading, to do the job.

I’d really, really love to experiment more with this, to get better at it and learn how to set up a great antenna for it (groundplane vertical would be nice), to learn how to set my audio filters to really narrow the audio down to the middle 1KHz of audio in the passband, and to find that favorite collection of remote stations that are highly reachable in case of emergency.

One final note on this rambling post: watch your radio power. This is a digital mode, and your radio’s duty cycle could approach 100% depending on transfer action. You could overheat your final amplifier or exceed your radio’s ability to cool itself. Luckily, my Yaesu FT-857 limits or shuts off the output power if it overheats to save itself. But unless I’m watching the needles on my antenna tuner, I wouldn’t know it was not transmitting. If your side suddenly stops being heard, the other station is left in the lurch and in a bad state, making it unusable by anybody until its timeout expires. Don’t be that guy. Drop your power to something reasonable; I had to set mine to 40W, but the audio level from the soundcard is only driving it to 30W peak, and still that’s almost too hot. Be ready for fan noise. A great antenna would be your friend in this case.

Overall, this has been a positive experience. I hope to use it more, and for more legitimate purposes than sending myself test messages. It’s a super-useful system, and it’s during these relaxed times that we practice and get better so we can do it reliably during stressful times.

Savage New Man

Gary Numan, Second Savage summer tour. 20180907 @ Mohawk.

Minimally chatty; said hello and went straight into the rocking. Consummate professional. Played a lot from “Savage”, a bit from “Broken”, a nice amount from “Jagged” (my favorite), a fair share from “The Pleasure Principle”, and even trotted out three Tubeway Army songs.

Long may he live.