In Sunday’s field day report there is a half-sentence that raises a question: the mail to HB9AK went out «not from Skywave, but directly from HAM-Tools». If you read the Skywave post from August, you are right to do a double take. You built Skywave, so why are you now sending Winlink mail from HAM-Tools? I never explained it properly. So here is the explanation, along with the answer to the question behind it: which of the two should you use?
In short: both are staying
Skywave is my standalone Winlink client for the Mac, open source under the MIT licence, introduced here in August. Nothing changes there: Skywave will keep being developed and remains the lean solution for anyone who just wants mail over radio and has no need for logging software.
The Winlink module in HAM-Tools is older than many people think. It arrived in the app with version 1.33, back then only over the internet. Version 1.34 added the radio paths ARDOP and VARA, and 1.39 the gateway directory. I never wrote a post of its own about it, because to me it felt like a by-product. That was a mistake, because by now it is the more complete of the two programs. This post makes up for it.
One core, two front ends
The reason I can maintain both with a clear conscience: the same engine sits under both. WinlinkKit is an open Swift package that handles all the Winlink plumbing, the B2F protocol, the FBB compression, the secure login. Skywave and the HAM-Tools module are two front ends on top of this one core. When I improve something in the protocol, both benefit. When a gateway behaves strangely, I debug it once.
That is also the difference from what HAM-Tools otherwise is: the app itself is not open source. The Winlink core underneath is, and if you want to see what a B2F handshake looks like, you can read it in the code.
What the module can do
Three paths into the Winlink network. Over the internet via Telnet to the CMS, which is the way to start, with server.winlink.org as the default and a test server that does not forward messages, in case you want to practise first. Over radio with ARDOP, and that is the path that matters to me: HAM-Tools ships with the ardopcf modem, it runs as a background process, no extra program, no audio routed through three tools. USB cable to the radio, set up the audio routing, PTT preferably via CAT, done. And if you have VARA, you can connect it via a Windows box on the network; HAM-Tools then talks to the modem over TCP.
The account is created on first contact with the system. The password is stored in the macOS Keychain, the callsign and locator come from the station data you have already maintained in HAM-Tools anyway. That is the first point where the module pulls ahead of the standalone client: it already knows who you are.
The gateway directory fetches the RMS gateways from the Winlink Web Services and shows them with distance and bearing from your locator, with band, dial frequency and bandwidth. Sort by distance, search by callsign, filter by band, set favourites. The app calculates the distance locally, and when you change your locator in the motorhome, the list re-sorts itself. It syncs at most once a day, with a search radius between 300 and 3000 km, the same restraint towards the Winlink infrastructure as in Skywave.
When composing, the module accepts a mix of callsigns and normal email addresses, separated by commas or semicolons. Attachments are compressed, images are scaled down automatically, with four size levels from around 50 KB up to the original, and the scaling can be switched without loss, because the app always recalculates from the original. That sounds like a minor detail, but it is the difference between a mail that goes through on 3613 kHz in two minutes and one that blows the gateway’s time window. On top of that: signatures with a per-message toggle, drafts, an outbox for the next sync, an address book with groups.
The mailbox is a proper mailbox: subfolders in the inbox, search by sender, recipient, subject and text, a bin. And every message is stored as its own .b2f file in the Winlink standard format on disk, under HAM-Tools/Winlink/Mailbox/. No database that locks you in.
What you need to know
A few stumbling blocks everyone runs into in the field: a mail to your own callsign does not come back from the CMS; for testing, use the callsign TEST, which replies automatically. Senders without a Winlink account end up in the spam filter, unless the subject starts with //WL2K. And the RMS gateways have time limits, typically 120 minutes per day and gateway. If you spend an hour shovelling pictures through with 100 watts at a field day, you have used up your afternoon.
So which one?
Skywave, if you want Winlink and nothing else. One program, one purpose, open code, small and quick to install. Ideal for the emergency comms laptop that should not run anything else.
HAM-Tools, if you already log in it. Then you have Winlink right next to your log, with the same station data, the same CAT cable and the same locator. At the field day, the mail to HB9AK went out from the same app the log was running in, without switching programs and without re-plugging a single cable. That is the moment the module earned the right not to be called a by-product any more.
And if you have both installed, you lose nothing: the mailboxes are separate, the account is the same, and the core that pushes the mails through the band is the same anyway.
What is still to come
The story I have been promising since August remains a promise: Winlink in everyday use, including what goes wrong. The everyday use itself has been running for a long time. Every few days I fetch my mail over radio, from the shack or from the motorhome, most recently on holiday in the mountains, where the mobile phone had nothing left and the radio still did. That is where the module has proven itself: connect briefly, fetch mail, done. All that is missing is the post about it.
You can find the help for the module, with all its settings, at toolbox.funkwelt.net/help/modules/winlink. Questions, bugs, gateway experiences: as always, feel free to send them my way.
73 de Chris, HB9HJI
Leave a Reply