RadioWiki · Tools
Do the math once.
12 calculators and reference cards for the questions that come up at the bench and in the truck. Each one links to the wiki pages that explain the why.
Program the radio
- 📻Repeater offset & toneType the output frequency, get the input, offset direction and exactly what to enter on the radio.
- 📋GMRS, FRS, MURS & WX channelsThe 22 shared channels with power limits and repeater inputs, MURS, NOAA weather, and every CTCSS/DCS tone.
- 🪪Band privileges by licence classCan a Technician transmit here? Pocket band chart for Tech, General and Extra with a frequency checker.
Antennas & signal
- 📏Antenna length calculatorDipole, ¼-wave, ⅝-wave, loop and J-pole cut lengths for any frequency, in feet or metres.
- 🔌Coax loss & ERPHow much of your power actually reaches the antenna through that run of RG-58 - and what your ERP is.
- 🏔️Radio horizon & line of sightTwo antenna heights → how far VHF/UHF or a mesh node can reach before the earth gets in the way.
- 🧮Radio unit convertersMHz ↔ wavelength, dBm ↔ watts, dB ↔ ratio, SWR ↔ return loss, S-units ↔ dBm.
- 🗺️Grid square & distanceLat/lon ↔ Maidenhead grid, plus the distance and bearing between two grids.