Fourth Class Amateur Radio Operator Exam: Selected 400 Questions and Answers By Tadahisa Yoshikawa This is a textbook for the Fourth Class Amateur Radio Operator license. I studied with this book and passed the regulations and radio engineering exams with a perfect score. While solving problems is important, it's crucial to grasp the key points for efficient learning. This time, I'm including a self-made memorization sheet that I compiled. I hope you will use this to efficiently pass the Amateur Radio Operator Class 4 exam! Instant purchase is welcome!