Hello Everyone! Welcome to my little corner of the radio spectrum. I’m Dr. Mahtab, and on air, I’m known by my official callsign, S21AMF. I am a licensed amateur radio operator based in Bangladesh, with a heart full of curiosity and a mind tuned to the endless possibilities of wireless communication.

My journey formally began in 2025 when I sat for the amateur radio examination. Passing that test was a massive milestone for me—it marked not just the acquisition of a unique callsign, but the beginning of an adventure into a world where signals cross vast oceans, voices bridge distant continents, and a simple piece of wire can become a literal gateway to the universe.

My Profession vs. My Passion

By profession, I am a medical doctor, dedicated to healthcare and human well-being. By passion, I am a ham radio enthusiast fascinated by radio frequency (RF), electronics, and global communication. This website, s21amf.com, serves as the perfect bridge between my professional life and my love for radio technology. It is my personal digital logbook—a dedicated space where I document everything I learn, build, and explore in this incredible realm.

Why Follow s21amf.com?

The world of amateur radio is vast, technical, and can sometimes feel overwhelming for beginners. I created this blog to share deeply informative, updated, and practical content that serves as a highly reliable resource for the ham radio community. On this site, you will find comprehensive guides organized into dedicated categories:

• Build & Operate & Antenna Lab: Practical, hands-on building projects, antenna theory, and step-by-step DIY installation guides to optimize your station.
• For New Hams & Licensing: Clear, step-by-step guidance on how to get licensed, study roadmaps, and navigate the official BTRC NOC (No Objection Certificate) process in Bangladesh.
• Rules & Safety: Deep insights into operating safely within the legal and regulatory frameworks established by the ITU (International Telecommunication Union) and BTRC.
• Emergency Radio & Tech Talk: Strategies for emergency communication preparedness (EmComm) during disasters, alongside high-tech discussions on modern digital modes and propagation.

An Independent, Passion-Driven Resource

A very important note for my readers: s21amf.com is completely independent. I do not sell any commercial products, and I do not promote specific gear or radio hardware for personal or financial gain. Every article, blueprint, and tutorial shared here is completely free—born solely from a genuine love for the hobby and a deep respect for the vibrant community that keeps the airwaves alive.

So, whether you are a seasoned operator with years of experience, a shortwave listener (SWL) chasing distant stations, or a tech enthusiast curious about the magic of radio frequencies— I am absolutely glad you’ve tuned in.

Thank you for visiting my digital shack. Let’s keep the frequencies alive!

73 and Good DX to all!
Dr. Mahtab (S21AMF)
Founder of s21amf.com