Ham utils library

Last updated: 2026-03-26 00:00

Ham utils library is a Java library that is intended to provide common useful functionality to avoid people needing to duplicate it.
Current functionality is:

• Get band by frequency
• Get a DXCC entity by callsign
• Get distance between two lat, lon pairs
• Get azimuth between two lat, lon pairs
• Get the bounds for a maidenhead locator

Some of these are complicated. For example, how to represent a band like 40m that has different ranges in Zone 1 and Zone 2.
Callsign to DXCC is tricky too.
As such, the behaviour of this might change over time.

It is currently in use in several of my projects - the WSPR activity page for one.

It is deliberately written in Java 8 to provide maximum compatibility.

It is published to the Maven repo, so it's easy to include.
You can find it at https://gitlab.com/g7vrd/ham-utils