https://www.bi4oae.top/ Practical amateur radio knowledge by BI4OAE en Sun, 18 Oct 2026 08:11:18 GMT https://www.bi4oae.top/blog/callsign-rules https://www.bi4oae.top/blog/callsign-rules Sun, 18 Oct 2026 00:00:00 GMT BI4OAE looks random at first glance, but every segment carries meaning. Here is the four-part structure of Chinese call signs, how it fits the ITU framework, and what you can and cannot read from a call sign. Licensing & Regulations https://www.bi4oae.top/blog/choosing-a-balun https://www.bi4oae.top/blog/choosing-a-balun Sun, 18 Oct 2026 00:00:00 GMT The wrong balun distorts your pattern, puts RF on the feedline, and heats up in the shack. The short answer: use a current balun wherever you can. Antennas & Propagation https://www.bi4oae.top/blog/choosing-coax https://www.bi4oae.top/blog/choosing-coax Sun, 18 Oct 2026 00:00:00 GMT Feed line is the part of the station that quietly eats your power. The only spec that matters is attenuation — and the nastiest trap in the hobby is a low SWR reading that hides a lossy line. Equipment & Gear https://www.bi4oae.top/blog/contest-basics https://www.bi4oae.top/blog/contest-basics Sun, 18 Oct 2026 00:00:00 GMT Contest radiosport looks like shouting call signs fast, but it is really about multipliers, clean exchanges and disciplined logging. A beginner's guide to CQ WW, ARRL Field Day and your first entry. Operating Skills https://www.bi4oae.top/blog/cross-region-operation https://www.bi4oae.top/blog/cross-region-operation Sun, 18 Oct 2026 00:00:00 GMT Can you take your handheld to another province — or another country? The answer depends on whether your station has a fixed location, what your license actually says, and whether a reciprocal agreement covers you. Licensing & Regulations https://www.bi4oae.top/blog/digital-voice-modes https://www.bi4oae.top/blog/digital-voice-modes Sun, 18 Oct 2026 00:00:00 GMT The three main amateur digital voice standards are mutually incompatible, and buying before checking what your local repeater does is the classic beginner mistake. Here is how they differ and how to choose. Digital Modes https://www.bi4oae.top/blog/efhw-antenna https://www.bi4oae.top/blog/efhw-antenna Sun, 18 Oct 2026 00:00:00 GMT An end-fed half wave covers 40 through 10 meters from one anchor point. Here is how the 49:1 transformer works, how to tune it, and how to keep common-mode current out of the shack. Antennas & Propagation https://www.bi4oae.top/blog/emcomm-frequencies https://www.bi4oae.top/blog/emcomm-frequencies Sun, 18 Oct 2026 00:00:00 GMT In a disaster you cannot browse for a clear channel. Plan a layered frequency card in advance — repeaters, simplex fallbacks, HF bands and digital modes. Emergency Communications https://www.bi4oae.top/blog/emcomm-ics205-communications-list https://www.bi4oae.top/blog/emcomm-ics205-communications-list Sun, 18 Oct 2026 00:00:00 GMT Real drills on two continents start from the same small task — writing down who you can reach, on which repeater, with what backup. The FEMA ICS-205A gives that task a format. Emergency Communications https://www.bi4oae.top/blog/emcomm-go-kit https://www.bi4oae.top/blog/emcomm-go-kit Sun, 18 Oct 2026 00:00:00 GMT A go-kit is not a shopping list. It is one box you can carry alone and have on the air within ten minutes — here is how to build, test and maintain it. Emergency Communications https://www.bi4oae.top/blog/exam-preparation https://www.bi4oae.top/blog/exam-preparation Sun, 18 Oct 2026 00:00:00 GMT The amateur radio exam is passable with method rather than heroics. The deciding factor is study order: regulations first, then technical foundations, then operating and safety, then wrong answers only in the final week. Getting Started https://www.bi4oae.top/blog/first-month-roadmap https://www.bi4oae.top/blog/first-month-roadmap Sun, 18 Oct 2026 00:00:00 GMT Passing the exam and being able to operate are two different skills. Here is a four-week plan for the month after your license arrives: listen first, learn the radio, join a net, then make your first contact. Getting Started https://www.bi4oae.top/blog/emergency-backup-communication https://www.bi4oae.top/blog/emergency-backup-communication Sun, 18 Oct 2026 00:00:00 GMT Dedicated networks need base stations, satellites need payloads, drones need launch conditions. When everything has a dependency, one radio, one battery and one wire still work. Emergency Communications https://www.bi4oae.top/blog/ft8-digital-mode https://www.bi4oae.top/blog/ft8-digital-mode Sun, 18 Oct 2026 00:00:00 GMT FT8 packs a complete contact into 15-second cycles and decodes signals about 20 dB below the noise floor. Here is how the protocol works, what it is genuinely good at, and where the criticism lands. Digital Modes https://www.bi4oae.top/blog/gray-line-propagation https://www.bi4oae.top/blog/gray-line-propagation Sun, 18 Oct 2026 00:00:00 GMT Low bands are absorbed by day and noisy by night. The gray line is the brief window when the D layer fades but the F layer stays — here is how to use it. Antennas & Propagation https://www.bi4oae.top/blog/ham-radio-activities-map https://www.bi4oae.top/blog/ham-radio-activities-map Sun, 18 Oct 2026 00:00:00 GMT DX chasing, local repeaters, digital modes, satellites, portable operating, emergency communications and contesting — seven directions one license can take you, with the gear and effort each one really needs. Getting Started https://www.bi4oae.top/blog/ham-radio-compliance-redlines https://www.bi4oae.top/blog/ham-radio-compliance-redlines Sun, 18 Oct 2026 00:00:00 GMT Buying a radio does not grant the right to transmit. From station licensing and type approval to modified equipment and interference, these are the lines that get operators into trouble — and the habits that keep you clear of them. Licensing & Regulations https://www.bi4oae.top/blog/ham-radio-handheld-buying https://www.bi4oae.top/blog/ham-radio-handheld-buying Sun, 18 Oct 2026 00:00:00 GMT A budget handheld is the right first radio for most new hams. Here is how the UV-5R, UV-K6, and UV-5RM differ, when to step up to DMR or a mobile, and what to check before ordering. Equipment & Gear https://www.bi4oae.top/blog/ham-radio-what-is https://www.bi4oae.top/blog/ham-radio-what-is Sun, 18 Oct 2026 00:00:00 GMT Amateur radio is a licensed, non-commercial radio service built for self-training, intercommunication and technical investigation. Here is what it actually is, what people do with it, and what it takes to get on the air. Getting Started https://www.bi4oae.top/blog/hf-antenna-basics https://www.bi4oae.top/blog/hf-antenna-basics Sun, 18 Oct 2026 00:00:00 GMT Dipoles, verticals, and Yagis each behave differently on the HF bands. Here is how a licensed ham chooses between them based on space, noise, and operating goals. Antennas & Propagation https://www.bi4oae.top/blog/hf-radio-buying https://www.bi4oae.top/blog/hf-radio-buying Sun, 18 Oct 2026 00:00:00 GMT 100 watts, 20 watts, or 10 watts; touchscreen or menus; with or without a built-in antenna tuner. The right first HF radio depends on where and how you plan to operate, not on the spec sheet alone. Equipment & Gear https://www.bi4oae.top/blog/itu-regions-and-iaru https://www.bi4oae.top/blog/itu-regions-and-iaru Sun, 18 Oct 2026 00:00:00 GMT The band edges you memorized are not universal. This article traces the chain from the ITU Radio Regulations through national regulators to IARU band plans, and explains why a neighboring country's 40-meter band may not match yours. Licensing & Regulations https://www.bi4oae.top/blog/keyboard-digital-modes https://www.bi4oae.top/blog/keyboard-digital-modes Sun, 18 Oct 2026 00:00:00 GMT FT8 dominates HF digital traffic, but it cannot hold a conversation. Here is what PSK31, RTTY, Olivia, MFSK and JS8Call each do, and how to pick the right one for what you are trying to achieve. Digital Modes https://www.bi4oae.top/blog/learning-cw https://www.bi4oae.top/blog/learning-cw Sun, 18 Oct 2026 00:00:00 GMT CW is the oldest digital mode and still the strongest per watt. Here is why it is worth learning, why the Koch method beats slow-speed practice, and a three-month schedule that fits real life. Operating Skills https://www.bi4oae.top/blog/logs-and-qsl https://www.bi4oae.top/blog/logs-and-qsl Sun, 18 Oct 2026 00:00:00 GMT A log is award evidence, a compliance record and a courtesy to the other station. Here is how LoTW, eQSL and paper QSL cards divide the work, plus a workflow that keeps years of data safe. Operating Skills https://www.bi4oae.top/blog/mmdvm-pi-star https://www.bi4oae.top/blog/mmdvm-pi-star Sun, 18 Oct 2026 00:00:00 GMT No DMR repeater in range? A Raspberry Pi, an MMDVM board and Pi-Star turn a few milliwatts into a personal gateway to the worldwide digital voice networks. Here is the full build and setup. Digital Modes https://www.bi4oae.top/blog/new-ham-order-of-operations https://www.bi4oae.top/blog/new-ham-order-of-operations Sun, 18 Oct 2026 00:00:00 GMT Once the exam is behind you, the next question is what to buy. The order matters more than the model: paperwork first, a modest UV handheld second, custom firmware last. Getting Started https://www.bi4oae.top/blog/pota-sota-portable https://www.bi4oae.top/blog/pota-sota-portable Sun, 18 Oct 2026 00:00:00 GMT POTA and SOTA both mean taking a radio outdoors, but their rules push you toward completely different kit. Here is what each programme requires, plus gear logic and a pre-departure checklist. Operating Skills https://www.bi4oae.top/blog/power-supply https://www.bi4oae.top/blog/power-supply Sun, 18 Oct 2026 00:00:00 GMT Most transceivers run on 13.8 V DC. Get the current rating right, understand the switching-versus-linear tradeoff, and know when a battery beats both — three habits that prevent most power problems. Equipment & Gear https://www.bi4oae.top/blog/rf-exposure-safety https://www.bi4oae.top/blog/rf-exposure-safety Sun, 18 Oct 2026 00:00:00 GMT Whether a handheld or a kilowatt matters is not a matter of opinion — it is arithmetic. Here is how MPE limits work, how to estimate a safe distance, and where the simple formula stops being valid. Licensing & Regulations https://www.bi4oae.top/blog/qso-etiquette https://www.bi4oae.top/blog/qso-etiquette Sun, 18 Oct 2026 00:00:00 GMT From listening before calling CQ to closing with a clean 73 — the fixed script behind a well-run QSO, plus the Q codes and RST reports every operator should know cold. Operating Skills https://www.bi4oae.top/blog/rtl-sdr-beginner https://www.bi4oae.top/blog/rtl-sdr-beginner Sun, 18 Oct 2026 00:00:00 GMT For about forty dollars and free software, a USB dongle receives everything from FM broadcast to aircraft, ships, and weather satellites — no license required. Here is how it works and how to start. Equipment & Gear https://www.bi4oae.top/blog/vertical-antenna-radials https://www.bi4oae.top/blog/vertical-antenna-radials Sun, 18 Oct 2026 00:00:00 GMT A quarter-wave vertical is only half an antenna; the other half lives in the ground. Here is how buried and elevated radials compare, and the three mistakes that waste the most power. Antennas & Propagation https://www.bi4oae.top/blog/winlink https://www.bi4oae.top/blog/winlink Sun, 18 Oct 2026 00:00:00 GMT Winlink moves email onto HF and VHF radio — and in the worst case, two stations can exchange mail directly with no gateway, no server and no internet at all. Emergency Communications https://www.bi4oae.top/blog/wspr https://www.bi4oae.top/blog/wspr Sun, 18 Oct 2026 00:00:00 GMT WSPR is a two-minute beacon mode that turns a few hundred milliwatts into a worldwide propagation sensor. Here is how the protocol works and how to use it to measure what your antenna is really doing. Digital Modes https://www.bi4oae.top/blog/welcome https://www.bi4oae.top/blog/welcome Sat, 17 Oct 2026 00:00:00 GMT The English edition of bi4oae.top — amateur radio knowledge, guides and tools by BI4OAE. Getting Started