Foundations of Amateur Radio

Cabrillo and ADIF are likely two terms you've heard if you've done anything with logging or contesting. So what are they, how do they work and why does it matter?

Let's start with Cabrillo. It's a file format used for submitting an electronic log to a contest manager. It was developed by Trey N5KO in 1999 for the ARRL. It's up to version 3.0, but the intent is that the older v2 files are still readable by todays programmes.

The aim of the Cabrillo format is to provide some meta information, like the contest name, the person who did the contest, what club they're part of, where they live, what category, etc.

After that, each contact is shown as a single line with a fixed format that shows the frequency, the mode, time-stamp, exchange and other pertinent details.

Significantly it does not contain any point information, because the intent is that the contest manager imports each log and their software calculates the actual score, dealing with the rules as defined by the contest, duplicates, multipliers etc.

The format for all of this is precisely defined and all the fields for a contact are required. The only other comment about Cabrillo is that it was developed to allow both humans and computers to read it easily.

At first glance, the ADIF format is all but the same. It deals with amateur radio stuff, contacts and the like.

But at second glance, ADIF, or Amateur Data Interchange Format is really not the same.

For starters, if you open up an ADIF file in a text editor you'll immediately notice that it's all but unreadable by a human. If you know what you're looking at you have a good chance to glean meaning, but at the first look it will appear as gobble-de-gook.

The ADIF file format is intended to be a way of exchanging any amateur information, such as awards multipliers, packet spot data, contest rules and it is intended to be expandable to include and incorporate any new kind of information as our hobby evolves.

There are countless ADIF fields, things like the reporting a short wave listener report, or an encryption key, or the grid square of the station, or the propagation mode, or any number of other values.

So, if you think of Cabrillo as the bare-bones of a contest contact log and ADIF as all the information you ever wanted to log and hadn't thought of logging, you'll have the right idea.

I should point out that both file formats are text. That means that if you open them up in a text editor you can look at them.

Word of warning for the unwary, you can really break an ADIF file by editing it in a text editor.

If you want to exchange amateur radio information with another amateur, use ADIF. If you want to submit a contest log, use Cabrillo.

I'm Onno VK6FLAB