Increase your Ham Radio Knowledge IQ

Callsign Lookup

Look up the current FCC license for a US amateur radio callsign — name, location, license class, and grid square.

Grid Square Calculator

Convert a latitude/longitude into a Maidenhead grid square, or use your current location — handy for contest exchanges.

Line-of-Sight Calculator

Estimate your radio horizon and signal range from antenna height, frequency, power, and antenna type — plotted as a range ring or directional beam wedge on a map.

Antenna Design

Dimension calculators for dipole/vertical, Yagi beam, J-pole, and Moxon antennas, built to your target frequency.

Takeoff Angle Calculator

Estimate the elevation takeoff angle and directionality of a vertical, dipole, or Yagi/beam antenna, plotted as pattern charts and on a map.

Cable Loss Calculator

Compare feedline loss and power delivered across common coax types for your frequency, length, and power.

Clock

Live local time and UTC (Zulu) side by side, handy for logging contacts and scheduling nets.

Shack Builder

Build out a radio, cable, meter, and antenna as a signal chain to see expected performance and total cost.

AREDN Network Planner

Place mesh nodes on a map, pick radios and antennas, and estimate which links are likely to work.

HF Propagation Predictor

A band × time heat map showing when to operate and which band to use between your QTH and a target station.

Can I Work It?

A quick chance-of-contact check between your QTH and a target station, factoring in your power, antenna, and height.

Grid Lookup Tool

Click anywhere on a map to get its Maidenhead grid square, lat/lon, nearest city, and local time vs. UTC.

Repeater Lookup

Find nearby repeaters using your location, a point on a map, or by state/city.

Satellite Tracker

Predict the next pass of a ham satellite for your location, with a live ground track and footprint map.

Satellite Pass Predictor

List the next several passes of a ham satellite for your location — rise, overhead, and set times with azimuth/elevation.