Ham Radio Terms and Specs, Explained in Plain English

Ham Radio Modulation and Standards

• Analog FM – This is the legacy standard for voice communication. It is widely compatible with older equipment and provides a straightforward, reliable way to communicate over short to medium distances.
• SSB (Single Sideband) – This is the primary mode for long-distance HF communication. It is more efficient than standard AM and is necessary for reaching international distances.
• DMR (Digital Mobile Radio) – This is a digital standard that uses TDMA (Time Division Multiple Access) to allow two conversations on a single frequency. It offers clearer audio and better performance in noisy environments.
• Bandwidth – This describes the width of the frequency space a signal occupies. A narrower bandwidth allows more users to share a band, while a wider bandwidth can provide higher-quality audio or data.
• Modulation Type – This refers to how the radio varies the carrier wave to carry information. Knowing whether a radio supports SSB, FM, or digital modes determines which types of communication you can perform.

Ham Radio Physical Specifications

• Duty Cycle – This is the amount of time a radio can transmit at full power before it needs to cool down. A higher duty cycle means the radio can stay on the air longer without overheating.
• Heat Dissipation – This refers to how the chassis manages the heat generated by the power amplifier. Better heat management allows for sustained operation at higher power levels.
• Weight (lbs/kg) – This is the physical mass of the unit. For mobile use, a lower weight is usually preferred for ease of installation, while base stations prioritize features over weight.
• IP Rating – This measures the device’s resistance to dust and water ingress. A higher IP rating, such as IP67, is necessary if the radio will be used in harsh outdoor environments.
• Connector Type – This is the physical port used to attach an antenna, such as SO-239 or BNC. You must ensure the connector matches your existing antenna cables.

Commonly Confused Ham Radio Terms

Several terms in the amateur radio world are often conflated by new buyers, leading to incorrect hardware selections.

Beginners can learn more by viewing the various types of ham radios explained.

SWR vs. Signal Strength

SWR measures the efficiency of your antenna match, while signal strength measures the actual power reaching the other person. A radio can have a perfect SWR but still have a weak signal if the antenna is poorly placed or the power output is too low.

HF vs. VHF/UHF

HF (High Frequency) is generally used for long-distance, “over-the-horizon” communication by bouncing signals off the atmosphere. VHF and UHF (Very High Frequency/Ultra High Frequency) are typically used for line-of-sight communication over shorter distances.

Sensitivity vs. Selectivity

Sensitivity is the ability to hear a very quiet signal, while selectivity is the ability to hear that signal without hearing the “noise” of the station next to it. A radio needs both to be effective in a crowded radio environment.

Before ordering any hardware, confirm the current local regulations for your specific location, as amateur radio rules vary significantly by country and region.

Reviewed by the Predicament Measures editorial team. Predicament Measures writes these guides from the 116 most-reviewed ham radios listings in our retail dataset, not from manufacturer copy.