All tools

Amplifier keying compatibility guide

Will your amplifier damage your transceiver? Keying interface requirements for tube amplifiers with modern radios.

APRS setup guide

How to set up APRS for position tracking, messaging, and weather reporting. Mobile, portable, and home station configurations.

Band plan comparison

Side-by-side amateur band allocations between countries. See where 40m ends in your country vs another.

Band plan reference

US amateur band plan with frequency segments, mode permissions, and license class requirements by band.

Callsign lookup

Look up a US amateur radio callsign. License class, name, location, grant and expiry dates.

RF connector identification guide

Identify and compare SO-239/PL-259, BNC, SMA, N-type, NMO, and other RF connectors used in amateur radio.

Contest operating primer

How to participate in amateur radio contests. Logging, exchanges, strategy, and getting started.

dB signal chain calculator

Trace your signal from radio to antenna. Add gains and losses to see power at each stage.

Digital mode setup guide

How to set up your station for FT8, FT4, JS8Call, and other digital modes. Step-by-step from radio to first QSO.

Dipole calculator

Half-wave dipole length by frequency. The 468/f formula with velocity factor adjustment.

DMR setup guide

How to set up your first DMR radio. Code plugs, talk groups, hotspots, and the DMR ecosystem explained.

DXCC awards guide

What DXCC is, how to pursue it, and how to confirm contacts for the DX Century Club award.

EchoLink and IRLP guide

How to use internet-linked repeaters. EchoLink and IRLP nodes explained for VHF/UHF operators.

Emergency and calling frequencies

Calling frequencies, emergency frequencies, and distress channels across amateur, marine, CB, GMRS, and FRS bands.

FCC Part 97 quick reference

The amateur radio rules that matter for daily operating. Power limits, identification, band restrictions, and prohibited communications.

Field Day guide

ARRL Field Day rules, setup, categories, and tips. The largest annual amateur radio event.

First HF station guide

What to buy for your first HF station. Equipment recommendations by budget with everything you need to get on the air.

Frequency / wavelength converter

Convert between frequency and wavelength in any unit. Identifies amateur and GMRS bands.

Station grounding guide

RF grounding, safety grounding, and lightning protection for amateur radio stations. What to ground, how to ground it, and why.

US amateur radio band chart

Complete US amateur band allocations showing frequencies, modes, power limits, and license class privileges for every band from 160 meters through 23 centimeters.

HT programming guide

How to program frequencies, CTCSS tones, and repeater offsets into your handheld radio. Covers CHIRP, manufacturer software, and manual keypad programming.

License class privileges

What bands and modes each US amateur license class can use. Technician, General, and Extra compared.

Link budget calculator

Will they hear you? TX power + antenna gain - path loss = signal at receiver. Shows link margin and whether the path works.

Logging software guide

Amateur radio logging software compared. N1MM+, Log4OM, HAMRS, CloudLog, and others for contest, general, and portable logging.

Microphone ↔ radio adapter finder

Every documented mic-to-radio pairing by connector family and microphone brand — Heil, MFJ, and OEM mics across all major transceiver lines. Click any cell.

Mobile HF installation guide

How to install HF radio in your vehicle. Antenna mounting, power wiring, noise suppression, and equipment selection.

Net operations guide

How amateur radio nets work. Net control procedures, check-in etiquette, and common net types explained.

NATO phonetic alphabet

The standard phonetic alphabet used in amateur radio, aviation, military, and maritime communications.

Portable station checklist

Packing checklist for POTA, SOTA, Field Day, and portable HF operations. Never forget a critical item.

POTA activation guide

How to activate a park for Parks on the Air. Equipment, setup, logging, and submitting your activation.

Power converter

Watts to dBm, dBW, ERP, and EIRP. Bidirectional with antenna gain input.

Power supply sizing guide

How many amps does your radio need? Size your power supply correctly for your transceiver and accessories.

HF propagation guide

How HF radio signals travel. Skip zones, the ionosphere, solar cycles, and which bands work when.

Q-signals reference

Common Q-codes used in amateur radio. QTH, QSL, QRM, QRZ, and more explained.

QSL and contact confirmation guide

How to confirm amateur radio contacts. QSL cards, Logbook of the World (LoTW), eQSL, and QRZ logbook explained.

Repeater operating guide

How to use amateur radio repeaters. Etiquette, procedures, and common mistakes new operators make.

Resonant frequency calculator

LC resonant frequency from inductance and capacitance. Three modes for solving any unknown in the LC circuit.

RF exposure / MPE calculator

FCC RF exposure compliance check. Power density vs MPE limit with minimum safe distance.

RFI troubleshooting guide

Radio frequency interference in your station. Identify and fix common sources of RFI, feedline radiation, and RF in the shack.

RST signal report guide

How to give and interpret signal reports in amateur radio. The RST system explained with real-world examples.

Amateur satellite guide

How to work amateur radio satellites. Equipment, tracking, and procedures for your first satellite QSO.

SOTA activation guide

How to activate a summit for Summits on the Air. Equipment, logistics, scoring, and safety for mountain-top amateur radio.

Speaker-mic compatibility guide

Which speaker-microphone fits your handheld radio. Connector types by manufacturer and compatible accessories.

SWR calculator

Standing wave ratio from forward and reflected power. Shows return loss, mismatch loss, and reflected percentage.

Full system designer

Pick a transceiver, amplifier, tuner, feedline, antenna, supply, and mic — then check the whole station for compatibility in one pass.

Tower and antenna safety guide

Climbing safety, installation guidelines, and when to hire a professional for amateur radio tower and antenna work.

Used radio buying guide

How to evaluate and buy used amateur radio equipment. What to check, what to avoid, and what a fair price looks like.

Antenna height and performance

How antenna height affects radiation angle, DX capability, and signal strength. Height recommendations by antenna type and operating goal.

Balun and unun selection guide

Which balun ratio to use for your antenna. 1:1, 4:1, 9:1, and 49:1 explained with antenna matching guidance.

Coax Loss calculator

Signal loss through coaxial cable by type, length, and frequency. Shows power reaching your antenna.

Feed line comparison

Compare two coax cables side by side at the same frequency and length. See which one wastes less power.

Gain Convert calculator

Convert between dBi and dBd. Shows the 2.15 dB offset and what the gain means in practice.

Ground Plane calculator

Quarter-wave ground plane antenna dimensions. Radial droop angle affects impedance match.

Impedance matching calculator

L-network component values to match two resistive impedances. Low-pass and high-pass solutions with Q factor.

J Pole calculator

J-pole antenna dimensions by frequency. Radiator, stub, gap, and feed point measurements.

Radio Horizon calculator

Maximum line-of-sight distance between two antennas based on height and Earth curvature.

Wire antenna selection guide

Which wire antenna to build for HF. Dipoles, EFHW, OCF, loops, and random wires compared with honest performance assessments.

Wire antenna designer

Dimensions for inverted-V, end-fed, G5RV, OCFD, and random wire antennas. Construction notes for each type.

Yagi antenna designer

Yagi antenna element lengths and spacings for 2-6 elements. Boom length, gain, and front-to-back ratio.

Battery Runtime calculator

How long your battery lasts given TX/RX/idle duty cycle. Chemistry-aware depth of discharge.

Duty-cycle power calculator

Average power draw from TX/RX/idle duty cycle. The number you need for battery and solar sizing.

Go-kit weight tracker

Track your portable radio kit weight. Pre-loaded common items. Tells you when it's too heavy for a hike-in.

Solar panel sizing

How big a solar panel for your radio setup. Panel wattage from daily energy need and peak sun hours.

CB antenna calculator

CB antenna types compared. Full-size whip through magnetic mount, with gain trade-offs and tuning guidance.

CB channel reference

All 40 US CB channels with frequencies and usage conventions. Emergency (9), trucker calling (19), and channels to avoid.

CB SWR tuning guide

Enter SWR on channels 1, 20, and 40. The tool reads the curve shape and tells you what to fix.

Channel plan builder

Build a channel list for your radio. Add channels, set frequencies and tones, export as CHIRP-compatible CSV.

CTCSS / DCS tone reference

All 50 CTCSS tones with Motorola, Midland, and Kenwood privacy code numbers, plus the 104 standard DCS codes. Search by frequency or code.

Repeater offset reference

Standard repeater input/output offsets by band. The quick reference for programming repeaters.

GMRS channel reference

All 30 GMRS channels with frequencies, power limits, repeater pairs, and FRS overlap. Filter by channel type.

PMR446 channel reference

All 16 PMR446 channels (8 analog + 8 digital) with frequencies. The EU personal radio service.

Repeater range estimator

Estimated repeater coverage radius from antenna height, power, and terrain.

FRS / GMRS / MURS / CB comparison

Side-by-side comparison of FRS, GMRS, MURS, and CB. License, power, range, cost, and equipment for each service.

Simplex range estimator

Estimated radio-to-radio range without a repeater. Both ends are usually low, so range is shorter than you think.

UHF CB channel reference (Australia)

All 80 Australian UHF CB channels with frequencies, repeater pairs, emergency channels, and power limits.