December 12th, 1901 is certainly a date with a historical relevance in radio transmissions.
In fact, at 04.30 GMT of that day, Guglielmo Marconi succeeds in sending the first transatlantic wireless communication.
Succeeding in this contact, Marconi demonstrate that radio waves transmissions could be transmitted even across the Atlantic ocean.
With this success Marconi, in addition, disproved detractors who told him, that the curvature of the earth would limit transmission to 200 miles or less.
The Facts
The Italian inventor received in St. John’s, Newfoundland, Canada, the letter S in morse code (three dots) transmitted from Poldhu, Cornwall, in England.
Marconi set up a specially designed wireless receiver in Newfoundland, Canada, using a coherer (a glass tube filled with iron filings) to conduct radio waves, and balloons and kites to lift the antenna as high as possible.
The station in Cornwall, England instead was composed by a twenty-four ships’ masts each 200 feet high, and the transmitter was powered by a 32 brake horsepower engine driving a 25 kilowatt alternator.
History says that detractors were correct when they declared that radio waves would not follow the curvature of the earth.
In fact today we know that radio waves had been headed into space from England when they were reflected off the ionosphere and finally bounced back down toward Canada.
Science demonstrated and explained this contact, made thanks to Radio wave propagation, just a few years later.
Therefore thinking in terms of amateur radio logic, we should consider this experiment as the first DX contact ever.
If you are interested in Marconi’s experiments and history, probably you can find interesting arguments and further details about this story here:
If you are not an amateur radio operator, DX could be considered a funny term.
In the amateur radio lingo:
DX is the telegraphic shorthand for distance or distant
DXing is the hobby of receiving and identifying distant radio signals.
Discovering a solution for limited space, the inverted L HF antenna emerges as a stellar performer. Half the size of a dipole, it ensures optimal installation in restricted areas, maintaining superb transmission (TX) and reception (RX) characteristics. Spectrum Communications’ multi-band version, featuring traps, proves even more space-friendly without compromising performance. A fiberglass pole offers sturdy support, while proper grounding, an RF choke, and occasional tuning contribute to a high-performing and reliable antenna system.
Streamlining FT8 Operations with Automation. The WSJT-X Controller simplifies FT8 operations by automating repetitive tasks in conjunction with WSJT-X. Designed to enhance efficiency, it facilitates tasks like responding to CQs, managing late 73 decodes, and seamlessly integrating with JTAlert and other add-ons. The program allows users to focus on productive QSO tasks while optimizing FT8 performance.
A brief overview of the current state of packet radio on the HF bands. In this comprehensive guide, the author navigates through HF packet radio, providing insights on the required equipment, protocols like Fx.25 and IL2P, and preferred ACDS segments. The post covers decoding and sending traffic, delving into optimal settings, recommended software, and common SSIDs. The author concludes by encouraging further exploration through additional reading and a Linux Packeteering series.
These frequencies have been adopted into the bandplans of each IARU region to be a focus for emergency communications in their areas. They are not absolute frequencies but instead are centres of activity and emergency communications may be found around 20kHz from these centres. Some countries may maintain other emergency frequencies in their own bandplans due to local requirements, QRM etc
In an innovative analysis, Michael G7VJR employs NeuralProphet to predict ham radio modes’ usage trends. The AI model, leveraging deep learning, forecasts a steady FT8 dominance, with slight declines in CW and Phone activities. This approach simplifies statistical predictions, showcasing the power of AI in understanding complex patterns and facilitating insightful time series projections. Access the freely available Club Log data for continuous exploration.
In this post by N6CTA, discover the conversion of the Yaesu ATAS-120A screwdriver antenna for portable use. The author details the creation of two sets of radials, 16 and 32 in 16ft lengths, aiming to optimize the efficiency of ground-mounted antennas. Additionally, insights are shared on attaching male quick disconnect blade tabs, with potential plans for a radial plate kit.
Discover a comprehensive solution for mapping Australian ham radio entities using data from the ACMA Public Register. This tool, developed in Delphi 7, generates KML files for Google Earth, showcasing repeaters, beacons, and operators across different prefixes. While respecting privacy regulations, the files provide valuable insights into the amateur radio landscape.
YaesuFT1000MK V stands out with improved close-spaced SSB transmit performance, reversing a trend seen in other modern radios. Featuring a class-A mode, it offers clean HV finals when kept out of ALC. However, two significant flaws persist: the noise blanker causes receiver IM distortion, and the transmitter lacks wave-shaping on CW, resulting in pronounced keyclicks. Preliminary tests reveal strong keyclicks +1kHz and -1kHz, prompting a combined modification to address both issues.
The author explores a portable version of the half-square antenna, typically a single-band structure. Using a 9:1 unun for versatility, they describe construction with speaker wire, deployment using collapsible poles, and field tests, achieving successful contacts on multiple bands. The article suggests efficient matching methods and concludes with the antenna’s integration into the author’s portable options.
The author explores enhancing the performance of a 7-meter fiberglass squid pole wire antenna for amateur radio. The wire, resonant at 10MHz, poses impedance challenges on various bands. Experimenting with direct coax feed and UN-UN transformers, the LDG Z11-Pro2 auto-tuner is found effective but may show deceptive SWR readings. The author employs adjustable UN-UN ratios and introduces a custom “porcupine” coil to optimize the antenna’s efficiency.
This project addresses the need for a 50 MHz Amplifier providing substantial power for Australian “Advanced Licensees” permitted to use 400W PEP in the 52-54 MHz band. In regions limited to 100W PEP due to TV channel usage, this initiative aims to enhance power output for transceivers with lower capabilities on the 6m band.
A detailed guide presents a simple 2-element quad antenna for 2m, offering ease of construction, portability, and efficient performance across the 144-148 MHz band. The design allows quick disassembly for storage and features adjustable polarization, making it ideal for various applications, including transmitter hunting and SSB operations.
This is a theoretical look at propagation on 630-Meters and 2200-Meters using ray tracing software. It expands on the brief discussion in the ARRL Handbooks. The Earth’s magnetic field affects 630-Meter and 2200-Meter band propagation. Lower ionization reduces absorption, aiding low-frequency propagation. Differences exist between bands, limited daytime sky-wave propagation. Sunrise/sunset show promise, yet mechanisms are unclear. Ducting possible at night in specific conditions. Negative ions enhance propagation. Inefficient antennas and high man-made noise are anticipated. Groundwave propagation is significant on 2200-Meters.
WSJT-X 2.7.0 RC4, released on March 11 2024, brings improvements primarily aimed at Fox-mode operators and enhancements to the QMAP companion program. Notable updates include QMAP’s ability to decode Q65 submodes with varying T/R sequence lengths, automatic adjustments of dial frequency and submode when clicking on stations in the Active Stations window, and a more compact file format for wideband data files. Users can now export a 3 kHz portion of a wideband data file as a standard WSJT-X *.wav file and send integer kHz dial frequency requests to WSJT-X with CTRL+click on QMAP’s waterfall. Minor User Interface enhancements have also been implemented. Additionally, WSJT-X now supports the decoding of MSK144 from the jt9[.exe] executable and includes modifications to handle issues arising from short callsign hashes in standard FT4/FT8 sub-bands. These updates streamline operations and improve the overall user experience for amateur radio enthusiasts.
WSJT-X 2.7.0-rc4 Release notes
Marc 11, 2024
WSJT-X 2.7.0 Release Candidate 4 brings some improvements for Fox-mode operators, new features for companion program QMAP, and a number of relatively minor enhancements and bug fixes.
QMAP enhancements — of particular interest to EME operators:
– QMAP now decodes Q65 submodes with both 60-second and 30-second T/R sequence lengths. Clicking on a resulting line in the WSJT-X Active Stations window automatically sets dial frequency and working submode as needed to call that station.
– QMAP operates in 60-second receive sequences, and its Q65 decoder starts at t=19.5, 30.0, 49.5, and 58.5 s into the sequence. Most decoded messages are displayed well before the end of the relevant time slot.
– A new, more compact file format is now used for wideband data files. A “Save decoded” option has been added to the Save menu.
– An option has been added to allow exporting a 3 kHz portion of a wideband data file as a standard WSJT-X *.wav file.
– CTRL+click on QMAP’s upper waterfall sends an integer kHz dial frequency request to WSJT-X.
– With focus on the WSJT-X main window, hit Alt+A on the keyboard to clear the Active Stations window.
– Many minor enhancements to the User Interface.
WSJT-X: – Enable decoding of MSK144 from the jt9[.exe] executable.
– Several changes to reduce problems experienced when (contrary to our recommendations) messages with short (10-bit) callsign hashes are used in standard FT4/FT8 sub-bands.
About Release Candidate versions
A release candidate (RC) version is a pre-release version of a software product that is considered to be feature-complete and relatively stable but may still undergo further testing before the final release. Release candidates are typically made available to a wider audience, including beta testers and the general public, to gather feedback and identify any remaining issues or bugs.
About WSJT-X
WSJT-X is a computer program designed to facilitate basic amateur radio communication using very weak signals. The first four letters in the program name stand for “Weak Signal communication by K1JT,” while the suffix “-X” indicates that WSJT-X started as an extended branch of an earlier program, WSJT, first released in 2001. Bill Somerville, G4WJS, Steve Franke, K9AN, and Nico Palermo, IV3NWV, have been major contributors to development of WSJT-X since 2013, 2015, and 2016, respectively.
The author explores the VP2E antenna, introduced by Ed Durrant DD5LP, for Portable Operations on the Air (POTA). Detailing its unique design, successful trials, and an unexpected propagation twist, the VP2E proves a promising addition to the author’s portable antenna arsenal.
Handmade drawing of a 3 bands single loop, portable quad antenna used by the author during his dx pedition in Kenya as 5H3FM. This antenna is done using 3 telescopic spreaders and the spreader kit for 1 element quad by spiderbeam.
This article explores budget-friendly methods for launching wire antennas into trees, comparing common options like slingshots and professional arborist tools. The author introduces a simple and cost-effective DIY approach using latex balloons, sand, and readily available materials for efficient antenna deployment in the field
OpenRTX is a free and open source firmware for digital ham radios. The firmware is designed with a top-down approach with the objectives of modularity, flexibility and high performance. Currently, it targets some Tytera Radioddity Baofeng digital radios
The author shares a unique experiment with a 200ft Grasswire antenna—laying wire directly on the ground. Despite inherent losses, the setup enables successful radio communication with a Kentucky station, highlighting the antenna’s practicality for portable use with minimal power.
The IARU Region 2 has established this voluntary band plan to better organize the use of our bands efficiently. To the extent possible, this band plan is harmonized with those of the other regions.
This project is a portable device used to automatically point a directional antenna towards an orbiting satellite. It takes all the effort out of little kids holding the antenna and figuring out where to point it. It allows students to talk through Amateur Radio satellites or download weather satellite images. Note: This is a complex DIY project for the advanced kit constructor.
The page for designing linked dipole antennas allows users to swiftly create a versatile multi-band antenna suitable for portable applications in outdoor settings, such as in the field or on mountain tops.
How to use AI (Artificial Intelligence) to identify Radio signals using a RTL SDR dongle and Linux (Ubuntu). This solution implement a framework using Keras and TensorFlow to learn and recognize the RF signals.
About LoRa, wireless communication technology designed to transmit data over long distances. LoRa provides a means for wireless data transmission over long distances with low power consumption. Practical applications of LoRa in amateur radio
The article details the design and construction of a four-band Moxon beam by a radio amateur. The beam, mounted atop a rooftop tower, aimed for gain over a dipole on 20 meters, cost under $500, and included additional bands. The design features fiberglass spreaders, four bands (20/15/10/6 meters), and a single feedpoint. The construction involved computer modeling, NEC source code, and specific dimensions. The article outlines the assembly, materials, and tuning process, including in-situ adjustments for optimal performance. Despite initial challenges, the beam improved signal strength and facilitated contacts on multiple bands, marking it as the best HF antenna the author has owned.
This is a Telegram bot written in Python that does ham radio call sign lookups via QRZ.com. This bot requires a paid QRZ.com account with XML access, in order to use the QRZ.com lookup feature of this bot a token for a Telegram bot
Ribbit is a novel digital text messaging mode for VHF/UHF communications for recreational and emergency use which radically increases the density of information transmitted by spectrum used. It leverages the computing power of the modern smartphone to increase the capabilities of any Handy Talkie without requiring any additional hardware or cable. A Ribbit message is fixed in duration at 1250 milliseconds. It is sent over audio modulation with a 2kHz bandwidth centered on 1.5kHz. It is preceded by 400ms of white noise to open analog squelch circuits.
This article provides a step-by-step guide for assembling a Raspberry Pi-based Satellite Tracker Interface, designed to work with Green Heron Engineering’s RT-21 controllers and MacDoppler software. The guide covers hardware assembly, SD card image installation, and system configuration for satellite tracking.
Arduino Digital Transceiver (ADX) is a low-cost HF transceiver for digital modes. This Arduino-based project, inspired by QDX, features four bands, including 80m and 20m, supporting FT8, FT4, JS8call, and WSPR. Designed for simplicity and affordability, it uses an Arduino Nano, SI5351 module, and CD2003GP receiver. The ADX project emphasizes easy procurement, construction, setup, and operation, making it an accessible option for QRP enthusiasts. The firmware update enhances functionality, including CAT control support.
M17 is a community of open source developers and radio enthusiasts. We are building understandable systems in support of the hackers and experimenters’ history of ham radio. M17 is developing open source hardware, software, and offers a complete digital radio protocol for data and voice, made by and for amateur radio operators. M17 voice mode uses the free and open Codec 2 voice encoder.
Discover the creation of a robust 2-meter, 3-element Yagi antenna using PVC pipe and window line. Designed for durability and portability, this innovative Yagi demonstrates enhanced signal strength, making it ideal for SSB and CW operation on the go.
The weather station described here uses a TTGO v3 1.6.2 module and various sensors. It displays the data on an OLED screen and transmits them among a choice of protocols to the APRS, APRS-IS, Wunderground servers or via an MQTT broker. APRS data is transmitted on 433.775 MHz (can be changed) using the LoRa protocol. APRS beacons picked up by iGate gateways are then transmitted to APRS servers.
Reviving the spirit of early ham radio experimentation, the CW Flea is a contemporary Morse code transmitter. Utilizing an Arduino Nano, Si5351 clock generator, and innovative design, this open-source project offers simplicity, flexibility, and easy tuning for aspiring radio enthusiasts.
Explore the design and testing of a cage dipole antenna for 6 meters. Through innovative construction, witness a remarkable 77% increase in bandwidth and improved impedance characteristics.
Amateur radio enthusiast Jean-Paul Suijs discusses combating manmade noise (QRM) in radio signals using AI. Detailing experiments with phase-shifting techniques and the self-learning nature of AI, he explores AI-based audio processing apps for real-time noise cancellation during radio contests, demonstrating results on both medium wave and shortwave bands.
A blog post about experimenting AI on writing blog post and creating pictures. This page includes also a youtube video by VE4VR experimenting ChatGPT over ham radio bands.
WaveTalkers asked AI itself what it thought. All of the content in the WaveTalkers AI Resources section is generated by AI. From the content to the code itself they will make every effort to showcase what works and what doesn’t along the way.
CQ Amateur radio 2019 article analyzing possible impacts of Artificial Intelligence in Amateur Radio operations. How to integrate AI in the radio shacks.
Unlock the secrets of RF signal optimization in a presentation covering Balun essentials, diverse types, SWR Analyzer checks, revealing results, Ferrite impedance measurements, and practical applications on feeders and house conductors.
Explore the detailed setup, essential software, and operational nuances for Greencube (IO-117), a Medium Earth Orbit (MEO) satellite with a 70cm digipeater, offering DX possibilities for amateur radio enthusiasts. From antenna configurations to software choices, this guide covers everything for a successful Greencube experience.
A tiny board, which allows a smartphone or similiar device to connect to the Baofeng UV5R radio via a TRRS audio connector. It allows for connecting the radio to a software TNC app such as APRSDroid or PocketPacket. Solder on the components, solder on the cables, then provide some stress relief, (I use solid-core wire and heat shrink tubing), and you can use your UV5R with your smartphone for APRS on the cheap.
Construct a portable 2m Slim Jim antenna for improved HT signal quality. Utilizing 450 ohm ladder line, the design offers flexibility, durability, and easy deployment. Tuning tips and mounting options enhance its efficiency in handheld transceiver communications
Author proves a swift and enjoyable method for scanning and exhibiting cherished QSL cards in the shack. Scanning each QSL card and displaying them. A Modern Solution for Scanning and Showcasing Your Favorite QSL Cards
DragonOS is a linux distribution dedicate to Software Defined Radio. It leverages the portability, security, and power of Lubuntu Linux as a delivery package and operating environment for a pre-installed suite of the most powerful and accessible open source SDR software. DragonOS has verified support for a range of inexpensive and powerful SDR hardware, including RTL-SDR, HackRF One, LimeSDR, BladeRF, and many others.
Website maintained by a group of amateur radio operators who would like to bring APRS via LoRa to OMs. Try it out, participate in the development of new iGates, trackers or write a documentation for a software/firmware
In pursuit of enhanced station efficiency, the author describes crafting an Arduino-based smart antenna switcher for an SO2R setup. Faced with manual antenna switching challenges during contests, the project utilizes a Logos Electromechanical 4×4 Driver Shield and a Power Screw shield for seamless functionality. Despite its raw appearance, the automatic switcher proves indispensable in contest scenarios, prompting considerations for future improvements and standardization of station control protocols.
The Ham Community WebLinks Directory is a curated collection of amateur radio link. It is designed for members to share exceptionally useful websites. Contributions follow guidelines, moderated by community moderators.
A low-cost Arduino project expanding on the button tutorial, where three inputs act as “buttons” generating Morse code on a WOTDUINO. This keyer, costing around £4, offers learning potential and hints at more complex ham radio applications.
Established in 1964, IRCA is a dedicated club focused on the pastime of tuning into distant stations on the AM broadcast band (510-1720 kHz). The club’s official publication, DX Monitor, is released 35 times annually. It is published weekly from October to March, twice in September and April, and monthly from May to August. DX Monitor includes members’ loggings, articles covering radio stations, receiver reviews, technical pieces, DX tips, and other content of relevance to Broadcast Band DX enthusiasts. Additionally, IRCA is affiliated with ANARC.
The NRC Archives feature past DX News and DX Audio Service publications, offering a glimpse into the “Heyday” of BCB DX. Subscribe to DX News for essential information, 20 bulletins annually, and membership privileges with discounted NRC products. New visitors can download a free sample copy of DX News
Navigating the Airwaves: A Comprehensive Guide to Amateur Radio Bands
Amateur radio, also known as ham radio, is a popular hobby that allows individuals to communicate with others around the world using their own radios using specific radio waves.
One of the key aspects of amateur radio is the use of specific frequency bands for communication.
In this article, we will explore the different amateur radio bands, their characteristics, propagation, and usage.
Understanding Amateur Radio Bands
Amateur radio bands are expressed in meters, representing the wavelength of the radio waves used for communication. The length of a wave is inversely proportional to its frequency, so longer waves have lower frequencies, and shorter waves have higher frequencies. The wavelength in meters can be calculated by dividing the speed of light (299,792,458 meters per second) by the frequency in hertz.
The customary band names provided below are primarily nominal wavelengths, not representing exact values. For instance, in the western hemisphere, the nominal 80-meter band spans approximately 85.7–74.9 meters, with an international portion from 85.7–83.3 meters. The so-called “17-meter” band actually covers 16.6–16.5 meters, while the nominal “15-meter” band ranges from 14.28–13.98 meters. It would be logically labeled as the “14-meter” band, but the established nomenclature has persisted due to historical usage in a shortwave broadcast band.
Frequency Allocations
The allocation of frequency bands for amateur radio varies from country to country and between ITU regions.
The International Telecommunication Union, in its international radio regulations, divides the world into three ITU regions for the purpose of managing the global radio spectrum.
Region 1 encompasses Europe, Africa, the Commonwealth of Independent States, Mongolia, and the Middle East west of the Persian Gulf, including Iraq.
Region 2 encompasses North and South America, including Greenland, the Caribbean, and a small number of the eastern Pacific Islands.
Region 3 comprises Asia east of and including Iran, and most of Oceania. The region excludes Central Asian and Eurasian countries formerly members of the Soviet Union.
Each ITU region establishes the authorized frequency ranges, and individual amateur stations are free to use any frequency within these ranges, depending on their class of station license. The allocation of bands and specific frequencies within each band is determined by international agreements and national regulations.
ITU allocation of frequencies for each region is made available for radio amateurs worldwide throught the IARU web site, where all band plans are published.
The Bands
The ham radio bands span a wide spectrum of frequencies, from low-frequency bands like LF and MF to high-frequency bands like HF, VHF, and UHF.
Each band has unique propagation characteristics, usage patterns, and regulations, facilitating diverse forms of communication among amateur radio enthusiasts worldwide
Below, for each band, we offer concise descriptions highlighting key characteristics, primary usage, and any applicable emission mode restrictions. Additionally, we provide links to real-time band monitoring through web SDR platforms, modern web based radio receivers, enabling users to listen in on these frequencies.
LF – Low Frequency Bands
2200 meters (135.7 – 137.8 kHz)
The 2200 meters band is just below the Asian and European longwave broadcast band and far below the commercial AM broadcast band. It is often used as a technical challenge due to the difficulty of long-distance (DX) propagation caused by higher D layer ionospheric absorption. It was formally allocated to amateurs at the 2007 on a secondary basis. Available on all ITU Zones, but not in all countries, this band is known to be notoriously noisy, particularly in the summer months.
Ducting might be possible on 2200-Meters in D region bite-outs.
Negative ions may help propagation
Groundwave propagation can be a big factor
MF – Medium Frequency Bands
630 meters (472 – 479 kHz)
The 630 meters band is just below the commercial AM broadcast band and the maritime radio band. It is also known as the “top band” and was formerly shared with the largely defunct Loran-A radionavigation system. Allocations in this band vary widely from country to country.
Propagation around sunrise and sunset can give good results
Ducting might be possible on 630-Meters in the nighttime electron density valley and in D region bite-outs.
Negative ions may help propagation
160 meters (1.800 – 2.000 MHz)
The 160 meters band is located just above the commercial AM broadcast band. It is often taken up as a technical challenge due to the difficulty of long-distance (DX) propagation caused by higher D layer ionospheric absorption. This band is known as the “top band” and is notorious for its noise, particularly during the summer months. This band is usable mostly during night time and during weak solar activities.
The 80 meters band is considered the most reliable all-season long-distance (DX) band. It is popular for DX contacts at night and reliable for medium-distance contacts during the day. In the US and Canada, a portion of this band allows for single-sideband voice and AM voice transmissions.
The 80 metes band goes from 3.5 to 4.0 MHz in ITU Region 2; generally 3.5–3.8 MHz in ITU Region 1, and 3.5–3.9 MHz in Region 3.
Upper part of the 80 meters Band in ITU Region 2 countries, is commonly named as 75 meters band.
This band is good for local communications during the day, and hardly ever good for communications over intercontinental distances during daylight hours. During late afternoon and night , when noise decreases, it can be effective even for worldwide communications.
The 60 meters band is a relatively new allocation and was originally only available in a small number of countries. It is now expanding, and in most countries, the allocation is broken into channels and may require a special licensing request. The 2015 ITU World Radiocommunications Conference approved a new worldwide frequency allocation for amateurs on a secondary basis.
The 40 meters band is considered the most reliable all-season long-distance (DX) band. It is popular for DX contacts at night and reliable for medium-distance contacts during the day. This band is now free of other users due to the shutdown of many shortwave broadcasting services. ITU Region 1 and Region 3 40 meters band range is from 7.000 to 7.200 MHz.
The 30 meters band is a very narrow band shared with non-amateur services. It is recommended for Morse code and data transmissions, and in some countries, amateur voice transmission is prohibited. It provides significant opportunities for long-distance communication at all points of the solar cycle. . WARC Band, contest free.
The 20 meters band is considered the most popular DX band and is usually most active during the daytime. It is commonly used for DX operations in all modes. This band permits long distance contacts, even when other bands are closed, and this is the reason why it is particularly crowded during contests.
Day sky waves with worldwide communications extending from dawn to dusk
Excellent night sky waves during high sunspot activity
Virtually no sky waves during minimum sunspot activity
17 meters (18.068 – 18.168 MHz)
The 17 meters band is similar to the 20 meters band but more sensitive to solar propagation minima and maxima. It is a very narrow band, just 100 kHz wide. It is also a WARC band, allocated to amateur radio use during the 1979 World Administrative Radio Conference.
Band is open at daytime and it usually opens before the others. . WARC Band, contest free.
The 15 meters band is most useful during solar maximum and generally a daytime band. Daytime sporadic E propagation occasionally occurs on this band, allowing for communication over distances of up to 1,500 km (1,000 miles).
Worldwide day and night sky waves during high sunspot activity
No night sky waves and only occasional day sky waves during minimum sunspot activity
12 meters (24.890 – 24.990 MHz)
The 12 meters band is mostly useful during the daytime but can open up for DX activity at night during solar maximum. It propagates via sporadic E and F2 propagation. WARC Band, contest free.
The 10 meters band is best for long-distance communication, especially during solar maximum. It offers short to medium-range groundwave propagation day or night. This band is also known for sporadic E propagation during the late spring and summer, allowing for short band openings into small geographic areas.
Worldwide sky waves in daytime and early evening hours during high sunspot activity
Very little day sky waves and virtually no night sky waves during minimum sunspot activity.
VHF Very-High Frequencies and UHF Ultra-High Frequencies
Frequencies above 30 MHz are referred to as Very High Frequency (VHF) and those above 300 MHz are called Ultra High Frequency (UHF). These bands have wider allocations, allowing for high-fidelity audio transmission modes and fast data transmission modes.
Propagation characteristics:
No ground wave propagation in sense of MF and HF ground waves.
(Beginning with 50–54 MHz) Direct and reflected waves describe line-of-sight radiation for these frequencies.
Only 6-meter band exhibits fairly constant propagation at distances of about 75 to 100 miles. Some ionospheric conditions permit propagation paths up to 2500 miles.
Frequencies at 144 MHz and above exhibit primarily line-of-sight communications with little ionospheric effects on this propagation. However, unusual propagation modes, such as ducting, will allow limited long-range communications.
Ham Radio Frequency Chart
Recommended Frequencies and Calling Frequencies
The table below provides guidance on recommended frequencies for specific modes of communication and special activities, including the calling frequencies.
This helps operators avoid interference and promotes responsible use of the radio spectrum, fostering a cooperative and respectful environment among radio operators.
The specified frequencies are generally associated with specific modes or activities (all frequencies in MHz) under normal conditions. These aren’t strict regulations, and increased activity, like during emergencies, DXpeditions, or contests, may lead to operations outside these ranges. No entity or individual has exclusive privileges to a frequency, as per Rule 97.101(b), emphasizing cooperation in channel selection and shared use.
It’s advisable, and common sense, for radio operators to check for existing usage before transmitting. If you’re the first to occupy a frequency, fellow operators should make efforts to minimize interference, acknowledging the challenge of achieving complete interference-free operation in today’s crowded bands.
Single Side Band Mode
Traditionally, 20 meters and above use Upper Sideband (USB), while 40 meters and below use Lower Sideband (LSB). However, the 60 meter band is an exception, employing Upper Sideband. This convention arose for convenience in early Single Sideband (SSB) transceiver design and persists. Where phone communication is allowed, Ham radio operators are legally permitted to use both sidebands.
The WARC bands, an abbreviation for “World Administrative Radio Conference” bands, are specific frequency allocations reserved for amateur radio usage. Established during te 1979 ITU Conference, these bands provide additional spectrum exclusively for amateur radio enthusiasts. WARC bands offer opportunities for experimentation, communication, and global connectivity, contributing to the diversity and vibrancy of the amateur radio community. WARC bands include 12 meters (24.890 – 24.990 MHz), 17 meters (18.068 – 18.168 MHz), and 30 meters (10.100 – 10.150 MHz).
By common agreement among ham radio operators, the WARC bands are not to be used for contesting.
These frequencies have been adopted into the bandplans of each IARU region to be a focus for emergency communications in their areas. They are not absolute frequencies but instead are centres of activity and emergency communications may be found around 20kHz from these centres. Some countries may maintain other emergency frequencies in their own bandplans due to local requirements, QRM etc
Amateur Radio bandplan in a large PDF A3 format valid for Serbia and Region 2
Final notes
Amateur radio bands play a crucial role in enabling communication among ham radio operators worldwide. From the low-frequency bands to the very-high and ultra-high frequencies, each band offers unique characteristics, propagation conditions, and usage patterns.
The information provided in this article is based on general knowledge of amateur radio bands. It is important to consult the specific regulations and band plans for your country or region before operating your radios on any amateur radio frequency.