What is the typical RF power output of airborne HF transmitters compared to VHF transmitters?

Airborne HF (High Frequency) transmitters are typically designed to operate at higher power outputs compared to VHF (Very High Frequency) transmitters due to the characteristics of the frequencies they use and their intended applications.

HF frequencies, which range from 3 to 30 MHz, are used for long-distance communication, making higher power levels advantageous for achieving reliable connections over vast distances, especially in aviation scenarios where communication can occur over hundreds or thousands of miles. A typical HF transmitter may have a power output around 100 watts, which is suitable for these long-range transmissions.

In contrast, VHF frequencies, ranging from 30 to 300 MHz, are generally suited for shorter-range communications and local transmissions. Consequently, a typical VHF transmitter might have a power output around 20 watts. This lower power is often sufficient for the shorter ranges associated with VHF communication, such as air traffic control and local communications.

The pairing of 100 watts for HF transmitters and 20 watts for VHF transmitters reflects the common power outputs you would expect in these applications, allowing for effective communication while taking into account the operational requirements and constraints of airborne systems.