BOZO’S CB RADIO PAGE FREE RF TOOLS
CB Radio Calculators
& RF Tools
Seven practical tools for antennas, coax, SWR and transmitter power. Built for everyday CB radio operators, from first-time setups to seasoned skip shooters.
01 / FEEDLINE
Coax Cable Loss
See how cable type and length affect how many watts actually arrive at your antenna.
Coax Loss
Estimate feedline attenuation and power at the antenna.
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Cable losses use approximate 30 MHz reference data scaled by √(frequency / 30 MHz). Real cable age, connectors, VSWR and manufacturer specifications can change the result. No mismatch loss is modeled.
02 / FREQUENCY
RF Wavelength
Convert frequency to wavelength in meters, feet and inches for your operating channel.
RF Wavelength
Convert a frequency to its free-space wavelength.
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Uses the speed of light in free space. Physical feedline wavelength depends on cable velocity factor.
03 / ANTENNAS
Quarter-Wave Antenna
Find a practical starting length for a quarter-wave whip or ground-plane radial.
Quarter-Wave Antenna
Estimate a ¼-wave radiator or ground-plane radial.
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This is a starting length for a straight element. Diameter, insulation, ground, loading coils and nearby objects affect actual tuning. Cut long, then measure and trim.
04 / ANTENNAS
Half-Wave Antenna
Estimate a half-wave wire element before making final adjustments with an analyzer.
Half-Wave Antenna
Estimate the full length of a ½-wave element.
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This is a starting length for a straight element. Diameter, insulation, ground, loading coils and nearby objects affect actual tuning. Cut long, then measure and trim.
05 / MATCHING
SWR & Reflected Power
Translate a measured SWR and forward power into a theoretical reflected-power estimate.
SWR & Reflected Power
Find reflection coefficient, reflected watts and mismatch loss.
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Ideal transmission-line relationship at the meter location. Reflected watts are not necessarily transmitter heat; feedline loss and tuner placement can change what is measured.
06 / POWER
dB & Watts Converter
Quickly convert dBm and dBW into watts or apply a known dB gain or loss.
dB & Watts Converter
Convert dBm, dBW and watts, or apply a power gain/loss.
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dB alone expresses a power ratio. Absolute power conversions require dBm (referenced to 1 mW) or dBW (referenced to 1 W).
07 / RADIATED POWER
Estimated ERP / EIRP
Combine transmitter power, estimated feedline attenuation and antenna gain.
Estimated ERP / EIRP
Combine TX watts, feedline loss and antenna gain.
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Cable losses use approximate 30 MHz reference data scaled by √(frequency / 30 MHz). Real cable age, connectors, VSWR and manufacturer specifications can change the result. No mismatch loss is modeled.