James Clerk Maxwell and the Prediction of Radio Waves

James Clerk Maxwell Statue

James Clerk Maxwell, a Scottish physicist, made an indelible mark on the field of physics with his profound contributions, most notably his theory of electromagnetism. Born in 1831, Maxwell’s work bridged the gap between the mechanical and the electromagnetic, a leap that would fundamentally alter our understanding of the physical world. In 1865, through “A … Read more

Understanding Radio Waves: Nature and Properties

Understanding Radio Waves: Nature and Properties

Radio waves, the unsung heroes of the electromagnetic spectrum, serve as the cornerstone of amateur radio, enabling enthusiasts to experiment, communicate, and explore a world invisible to the naked eye. These waves, oscillating electric and magnetic fields that travel through space at the speed of light, embody the confluence of physics, engineering, and art that … Read more

It’s Time!

Ham Radio Academy

Remember when I said there would be Changes Coming….? Well, It’s time! Over the next couple of weeks the site is going to get an overhaul. A big one. I’ve removed the shop and practice test links from the menu, because, well, they were outdated garbage. I’ll add them back eventually, once I figure out … Read more

Changes Coming….

So uh, yeah. I made this website then walked away from it. Starting early next year, I’m giving this place an overhaul. I mean, stuff is way out of date, the practice tests are messed up, and I haven’t actually written anything in idk even how long. You might notice the “Ham Radio for Smart … Read more

New Technician Practice Exam!

[note: this post is almost 4 years old (as of March 2024), the exams have changed, and well, its just outdated. You’re still welcome to use this. Understand its not updated, it has errors, and it may stop working at some point.] Hey everyone, just wanted to let you know that I’ve added a Technician … Read more

Antenna Gain dBi vs. dBd

Effective Radiated Power

How does antenna gain stated in dBi compare to gain stated in dBd for the same antenna? A. dBi gain figures are 2.15 dB lower than dBd gain figuresB. dBi gain figures are 2.15 dB higher than dBd gain figuresC. dBi gain figures are the same as the square root of dBd gain figures multiplied … Read more

PIN Diode RF Attenuation

Microwave Switch

What is used to control the attenuation of RF signals by a PIN diode? A. Forward DC bias current B. A sub-harmonic pump signal C. Reverse voltage larger than the RF signal D. Capacitance of an RF coupling capacitor [E6B11] This question from the new Amateur Extra question pool dives head first into the operation … Read more

Determine Maximum Usable Frequency

Determine Maximum Usable Frequency

What is a reliable way to determine if the MUF is high enough to support skip propagation between your station and a distant location on frequencies between 14 and 30 MHz? A. Listen for signals from an international beacon in the frequency range you plan to useB. Send a series of dots on the band … Read more

Estimating Maximum Permissible Exposure

Estimating Maximum Permissible Exposure

Which of the following properties is important in estimating whether an RF signal exceeds the maximum permissible exposure (MPE)? A. Its duty cycleB. Its frequencyC. Its power densityD. All these choices are correct [G0A02] Let’s look at each possible answer individually, and then we’ll decide which is correct. A. Its duty cycle. Duty Cycle refers … Read more