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Over two decades of historical DX spots and news are archived on this Japanese resource, providing a retrospective look at amateur radio propagation and activity across various bands. The content is organized chronologically, with separate sections for _50MHz_, _HF DX_, _144MHz_, _EME_, and Satellite clusters, detailing spot data from as early as 1996 through 2014. This extensive archive serves as a valuable historical record for analyzing long-term propagation trends and significant DXpeditions from a Japanese perspective, offering insights into band openings and rare entity activations. The resource also includes links to other DX news sites like _425 DX News_ and _Ohio/Penn DX Bulletin_, along with QSL manager lookups and callbook services, enhancing its utility as a comprehensive DX information hub. While the primary cluster data is historical, the compilation of external links points to active resources for current DX operations. This makes it a useful reference for contesters and DXers researching past conditions or seeking information on specific DX entities and their QSL routes.

Closer pictures of Yaesu VX-150

The San Diego Six SHooters Amateur Radio Club, established in April 2001, is dedicated to promoting all modes of operation on the Six Meter Amateur Radio Band.

With over 20 years of experience, Proyecto 4 operates as a specialized ham radio retailer in Madrid, Spain, providing a diverse inventory of transceivers, antennas, and related accessories. The store features popular models like the _ICOM IC-705_ and _ICOM IC-7300MK2_, alongside Yaesu transceivers such as the _FTX-1 Optima_, which delivers 100W on HF and 50W on V/UHF bands. The product range includes mobile and portable antennas, such as the D-Original DX-NR770HB, offering 3 dB gain on 144 MHz and 5.5 dB on 430 MHz, and the Diamond RH-770 with a BNC connector. CB radio enthusiasts can find the Anytone CB SMART II AM/FM transceptor and the Telecom LS145 mobile antenna, rated for 500W and 4 dB gain on 26-30 MHz. Proyecto 4 emphasizes its in-house technical service, inviting customers to visit their laboratory for repairs and technical consultations via sergio@proyecto4.com. The store also highlights customer reviews and offers promotions like Yaesu Cashback, providing savings up to 100€.

The **HFRadioSales.au** resource provides a commercial outlet for amateur and commercial radio operators seeking HF SSB equipment and related services. It focuses on the Australian market, offering new and refurbished transceivers, antennas, tuners, and a wide array of spare parts for brands like Codan, Barrett, and Qmac. The site details its role as a licensed dealer for new Barrett Communications and Codan radio and antenna systems, including specific models such as the Barrett 4050, 2050, and 950, and Codan Envoy and NGT series. This platform supports various applications, including vehicle, 4WD, outback, marine, and base station setups, catering to networks like HF Radio Club, VKS737, and RFDS. It also features commercial-grade antennas from Bushcomm, such as the BBA100C and SWC100, available for fast shipping from their Queensland warehouse. The site includes an FAQ section with general information on mobile HF communications in Australia and timelines for specific transceiver models.

The Kenwood TS-950S and TS-950SD HF transceivers are fine radios. However, many, if not all, of them were produced with a design flaw which allows the RG GAIN control to cease function in the presence of a strong signal IF the AGC has been turned OFF

Generic PI4 + CW + Carrier Arduino Beacon Controller with interfacing to Analog Devices AD9833 DDS AD9850 DDS, AD9851 DDS, AD9912 DDS , AD9913 DDS, ADF4350 and ADF4351 synthesizers, ADF5355 synthesizer, ADF5356 synthesizer, Radio modulated by an audio soft-DDS Reverse DDS, RDDS microwave unit, Silicon Labs Si5351A programmable clock generator, Silicon Labs Si570 programmable XO/VCXO, Texas Instruments LMX2541 synthesizer

This page is dedicated to helping 850 owners keep their radios on the air

Modifications and messages about the Yaesu FT-450

50 MHz meteor scatter offers a unique opportunity for amateur radio operators to make long-distance QSOs, even when the band appears dead. Meteor scatter involves reflecting radio waves off the ionized trails left by meteors burning up in the upper atmosphere, typically around 105 km high. These trails can facilitate contacts over distances up to approximately 2,300 km. The technique is particularly effective during meteor showers, which increase the number of meteors and thus the chances of successful QSOs. However, random meteors can also be used to achieve contacts, especially on the 50 MHz band, where the longer reflection time compared to 144 MHz makes it easier to work meteor scatter. Operators should be prepared to make QSOs in short bursts, often lasting only a few seconds. The IARU Region 1 meteor scatter procedure recommends using 2.5-minute periods for telegraphy and 1-minute periods for SSB, though shorter periods can be arranged. For 50 MHz SSB, 15-second timing is often used to maximize the chances of completing a contact. The procedure involves specific timing for transmissions based on direction and requires both operators to confirm receipt of callsigns and reports to complete a QSO. Understanding the geometry of meteor scatter, including the optimal radiation angles and the concept of 'hot spots,' is crucial. These hot spots are areas where reflections are most likely to occur, influenced by the Earth's rotation and the path of the meteors. Proper antenna setup, including elevation control and beam direction, can significantly enhance the chances of successful meteor scatter QSOs.

Presents the Aceco product line, focusing on their range of frequency counters, RF testers, and specialized bug finders. It details the capabilities of the _FC-1000_ and _FC-2000_ series as user-friendly, affordable frequency counters operating up to 3 GHz. The resource also highlights the _FC-3002_ as a portable RF finder capable of automatically tuning _ICOM CI-V_ or AOR scanners to detected signals, emphasizing its utility in secure monitoring. Furthermore, it describes the _FC-5000_ series as a wideband FM receiver that rapidly locks onto and demodulates FM signals, outputting audio through a built-in speaker, making it suitable for counter-surveillance and radio communication testing. The page provides technical specifications and operational distinctions for each product series. The content is structured to differentiate between the core functions of frequency measurement, signal tracing, and FM signal demodulation across the various models. It clarifies that these devices are not traditional scanners but offer faster signal acquisition for specific applications. The information is presented in both English and German, with a note indicating ongoing translation efforts for the German sections. The resource serves as a product catalog and technical overview for Aceco devices, distributed by WiMo Antennen und Elektronik GmbH, providing essential details for potential buyers interested in RF measurement and surveillance tools.

An old post by John Doty about effects of noise in longwire antenna.

How to build your own beverage antenna for 80-160 meters band by K5ZD

An interesting article by K3DAV comparing the COMET CHA250B to other HF multiband vertical antennas

Details Guglielmo Marconi's foundational contributions to radio communication, highlighting his 1898 Patent **7777** which introduced tuning circuits for independent simultaneous communications. Chronicles the historic transatlantic reception of the Morse code letter 'S' on December 12, 1901, from Poldhu, Cornwall, to St. John's, Newfoundland, a distance of over _3,500 kilometers_. The exhibit showcases early Marconi 10-inch spark transmitters, identical to those used on the _Titanic_, alongside Canadian Marconi crystal detector models. It also features high-end commercial receivers like the IP501, weighing **87 pounds** and originally priced at $595.00, demonstrating the robust construction and technological advancements of the era.

The UK amateur radio licensing scheme features three distinct tiers: Foundation, Intermediate, and Full, each granting specific operating privileges. For instance, the **Foundation Licence** permits a maximum of 10 watts output power on most allocated bands, with restricted band access. The Intermediate Licence allows up to 50 watts, while the **Full Licence** grants access to the maximum UK legal power limits and all available amateur radio band allocations. UK call sign prefixes and formats provide insights into the licensee's class and the approximate issuance date. For example, M3, M6, and M7 prefixes with three letters denote Foundation Licences issued from 2002, 2008, and 2018 respectively. Intermediate Licences, often starting with "2E0" or "2E1" followed by three letters, were issued from 1991 onwards. Full Licences encompass a broader range of prefixes like G2, G3, G4, G0, and M0, with varying letter counts indicating different historical license classes and issuance periods, such as G3 plus three letters issued between 1946 and 1971. Special prefixes like GB are reserved for repeaters, beacons, data mailboxes, and special event stations, with specific numerical sequences (e.g., GB3 for repeaters, GB7 for data repeaters/mailboxes) indicating their function. Optional prefixes such as GC, GD, GI, GM, and GW denote specific UK countries (e.g., Wales, Isle of Man, Northern Ireland, Scotland, England) and can also signify club stations.

Original drawing and design of a 4 and 7 elements yagi antenna for 50 Mhz

This document details the design and construction of a Vinecom 6N4 dual-band Yagi antenna for the 50MHz (6-meter) and 70MHz (4-meter) amateur radio bands. The antenna features 9 total elements (4 elements for 50MHz, 5 elements for 70MHz) on a 4.236-meter aluminum boom. Computer simulations using MMANA software predict 7.21 dBd gain on both bands with front-to-back ratios of 16.01dB (6m) and 15.37dB (4m). The design uses 12.7mm diameter elements mounted on a 32mm square boom, weighing 5.7kg total. Practical measurements with an MFJ-269 analyzer confirmed good SWR performance across both bands after element length adjustments.

HB9DNU Karlheinz's blog, hosted on Blogger, presents a collection of personal reflections and observations, predominantly in German. The content spans various non-amateur radio subjects, including Swiss political initiatives, economic discussions concerning banks like UBS, and social commentary. For instance, an entry from February 2008 details the Swiss vote on a combat jet noise initiative, highlighting the debate between tourism concerns and national security. Another post from October 2008 critiques the 500 billion Euro bailout package for banks, calculating its per-capita cost for German citizens and referencing earlier blog entries from March 2006 and June 2007 that discussed UBS salaries and Raiffeisenbank issues. These entries often reflect Karlheinz's personal perspective on current events. The blog also includes lighter, more personal notes, such as a February 2009 entry about a video produced by his grandson, and observations on local events like a bird exhibition in Contone or a scenic train ride through the Centovalli, demonstrating a broad range of interests beyond the ham radio hobby.

Free memory backup/restore program for the Yaesu VR-5000 receiver.

If your doing any home brewing gear for ham radio its a great idea to have a dummy load. This will to your radio be the perfect antenna...it will never radiate but your radio sees a perfect 50 Ohm impedance.

The Amateur Radio Society of ROYAL SIGNALS (British Army), 1550 Members. MERCURY Journal issued three times a year (Editor G3NVK) Regular (daily) Nets. Awards and Contests. Own QSL Bureau. E-mail List Server open to all. Regularly updated Web Site (Web Master G3NVK) includes EASYMAIL facility, Guest Book, Photo Gallery, Society Rules, Military Museums.

PSK31 is a digital communications mode which is intended for live keyboard-to-keyboard conversations, similar to radioteletype. Its data rate is 31.25 bauds (about 50 word-per-minute), and its narrow bandwidth (approximately 60 Hz at -26 dB) reduces its susceptibility to noise.

Provides a robust contest logging solution for Windows users, supporting over **500** distinct amateur radio contests. The software integrates _digital modes_ and offers comprehensive logging features essential for competitive operating. It facilitates efficient entry, real-time scoring, and post-contest log submission in standard formats. Developed and maintained by K1LZ and a dedicated team, DXLog.net is provided free of charge to the amateur radio community. Users can access support and report bugs via the dedicated groups.io forum, ensuring ongoing development and user assistance. The platform includes detailed release notes and an archive of support information, aiding operators in maximizing their contest performance.

Six meters radio club, promote and preserve 50 mhz operations in italy

A general guide to D-STAR. The purpose of D-STAR is to allow HAM Radio operators to speak further and clearer using digital voice while sending data from 1200 BPS on up at the same time.

One of several Colombian broadcasting networks heard on AM and FM and worldwide on 5076 kHz in the 60 meter band.

The NCDXF/IARU International Beacon Project operates a worldwide network of 18 high-frequency radio beacons, continuously transmitting on 14.100, 18.110, 21.150, 24.930, and 28.200 MHz. These beacons, initially launched in 1979 with a single station and expanded to the current 18-beacon system in 1995, provide reliable signals for both amateur and commercial users to assess current **ionospheric propagation** conditions. The system's design, construction, and operation are managed by volunteers, covering hardware and shipping costs. The resource details the evolution of the beacon network, including the transition from Kenwood TS-50s transmitters to Icom IC-7200 radios with a new controller design implemented in 2015. It explains how listening for these 100-watt signals, transmitted to vertical antennas, allows operators to determine band openings and optimal propagation paths globally. The content also references three QST articles providing historical context and technical specifics of the beacon project. Practical information includes methods for identifying transmitting beacons via a schedule or specialized software like FAROS and Skimmer, which integrates with the **Reverse Beacon Network** for automated monitoring.

Specializing in antique, vintage and tube radio repair, all makes. Transistor radio repair- from the 50's to the present. Free estimates.

In this youtube video G8GKC M0KKW and 2E0IAJ from Icom UK give a global overview of the ICOM IC-7300 HF 50 70MHz Software Defined Radio transceiver

Somalia

Presents a curated collection of newsletters dedicated to _Earth-Moon-Earth_ (EME) communications, primarily focusing on the 432 MHz band and higher microwave frequencies. The resource details various EME DX experiences and news contributions from operators like K2UYH (W6/PA0ZN), offering insights into successful moonbounce contacts and operational strategies. It serves as an archive of specialized content for those engaged in or interested in extreme weak-signal propagation via the moon. The newsletters provide practical information on achieving EME contacts, often including details on station setups, antenna arrays, and signal reports from challenging DX. For instance, operators might report achieving contacts over **750,000 km** round trip, demonstrating the feasibility of long-distance communication on UHF and microwave bands. The content differentiates itself by concentrating on the unique technical and operational aspects of EME, which contrasts significantly with terrestrial DXing, providing a specialized knowledge base for advanced amateur radio operators.

ARCI is a family of over 500 people dedicated to the preservation of antique radios and related items. ARCI hosts the annual RADIOFEST meet in August.

Presents a QRP AM/CW transmitter project specifically designed for the 10-meter band, utilizing a crystal oscillator and a collector-modulated AM oscillator. The design employs a 2N2219(A) transistor in a Colpitts configuration, generating 100 to 350 mW of RF output power depending on the 9-18 Volt supply voltage and modulation depth. Frequency stability is maintained by a 28 MHz crystal, with fine-tuning possible via a Ct1 trimmer capacitor for approximately 1 kHz adjustment. The resource details the RF oscillator stage, implemented with a 2N2219 NPN transistor, emphasizing frequency stability and low power dissipation. It also covers the amplitude modulation stage, managed by a 2N2905 PNP transistor, which impresses audio information onto the carrier. Selective components (C3, C4, C7, C5) enhance voice frequencies within a +/- 5 kHz bandwidth, and modulation depth is controlled by R2 and R3. The project includes a 3-element L-type narrow bandpass filter (Ct3, L3, C10) to suppress harmonics and ensure a clean output signal. The project provides a complete schematic diagram, a comprehensive parts list including specific capacitor, resistor, and inductor values, and construction notes for the coils (L1, L2, L3). It also offers practical advice on enclosure requirements, suggesting an all-metal case or a PVC box with graphite paint for RF shielding. Operational parameters such as current draw (27mA@9V to 45mA@16V) and input impedance (50 Ohms) are specified, alongside guidance on antenna matching and the importance of a valid amateur radio license for 10-meter band operation.

This modification will expand the tx frequency range of the Yaesu FT-991 from allowing just ham radio bands, to all bands 1.8 - 30MHz and 50-54 MHz.This information is solely for use by licensed members of MARS (Military Affiliate Radio System) or CAP (Civil Air Patrol)

Founded in 2000 by Jim Weidner, K2JXW, a licensed ham operator for over 50 years, the ARLHS is the only society of its kind devoted to Maritime Communications, Ham Radio, Lighthouses, and Lightships.

QST Magazine Product Reviews - Key Measurements Summary - HF-Transceivers or Receivers. Compares Yaesu FTDX5000, Elecraft K3, Flex 5000 and Kenwood TS-590S

UKSMG news, message board, and articles dedicated to encouraging amateur radio on 50MHz around the world.

The webpage provides guidance on working 6 Meter DX, focusing on effective operating habits, preparation, and knowledge of the band. It emphasizes the importance of monitoring, clear frequencies, and using CW for weak signals. It also mentions the significance of knowing countries and individual stations on the air to increase chances of working DX. The page recommends utilizing resources like newsletters and websites to stay updated on 6-meter activity and offers suggestions for improving operating skills.

CLARC was founded in 1987 as an ARRL Special Services Club and is an IRS 501(c)3 not-for-profit organization serving the NASA/Clear Lake area of Houston, Texas.

Over two decades ago, the Kenwood TS-850S HF transceiver established itself as a robust performer, known for its excellent receiver and versatile operating features. This vintage rig, often found on the used market, continues to be a favorite among many amateur radio operators for its solid construction and reliable performance across the HF bands. Adrian's Yahoo! Group provided a dedicated forum for TS-850S owners to exchange insights, troubleshoot issues, and share modifications or operational tips. Such community-driven platforms were crucial for extending the operational life and maximizing the utility of classic transceivers, fostering a spirit of mutual aid among hams. Discussions frequently covered topics like DSP unit upgrades, common repair challenges, and optimizing the rig for contesting or DXing, reflecting the enduring interest in this particular Kenwood model.

Approximately 1,500 unique DX spots are typically visible on the _ODXC Web Monitor_ at any given time, providing real-time intelligence for amateur radio operators seeking DX contacts. This service aggregates spotting data from the _RW3XA-8 Obninsk DX Cluster_ node, presenting it through a straightforward web interface. Users can monitor current activity across various HF bands, identifying stations calling CQ DX or reporting rare entities. The platform supports both traditional telnet access for those using dedicated cluster clients and a Java-based web interface, catering to different operational preferences. It serves as a practical tool for contesters and DXers to track propagation, identify active stations, and plan their operating strategies. The cluster data includes callsigns, frequencies, modes, and spotter information, crucial for effective DX hunting. Integration with other spotting networks like _RBN_ and _PSK Reporter_ enhances its utility.

The Yaesu VX-5R, manufactured between 199x and 200x, offers a transmit frequency range covering 50-52 MHz, 144-146 MHz, and 430-440 MHz for European models, with US versions extending to 50-54 MHz, 144-148 MHz, and 430-450 MHz. Its receiver boasts an impressive wideband capability from 0.5 MHz to 999 MHz, with cellular frequencies blocked in some regions. The unit provides up to 5 watts RF output on 6 meters and 2 meters, and 4.5 watts on 70 centimeters, with selectable lower power settings down to 300 mW. This handheld transceiver utilizes a double conversion superheterodyne receiver system, featuring a 47.25 MHz first IF for FM and 45.8 MHz for WFM. Key specifications include a frequency stability of ±5 ppm across a wide temperature range and a current drain of 25-150 mA on receive. The VX-5R supports 220 regular memory channels with alpha tags, 3 home channels, and 10 NOAA weather channels, all stored in non-volatile EEPROM. Additional features include CTCSS/PL and DCS with tone search, ARS, ARTS, an internal voltmeter, and a Spectra-Scope. The device operates on a 7.2 VDC battery pack or 10-16 VDC external power, weighing 255 grams with dimensions of 58x88x27 mm. The VX-5R was also available as the metallic silver VX-5RS.

A monster magnetic loop antenna for 160 meters band. This Magnetic loop is optimized for 1840 Khz + 50 Khz. PDF Article published on La Radiospecola 10.22

This document details the design and construction of the PA70H, a 50-watt RF amplifier for the 70MHz (4-meter) amateur radio band. Built around the Mitsubishi RD70HVF1 MOSFET transistor, the amplifier delivers 45-55W output with 3-5W input power while operating on 13.8V DC at approximately 7-8A. The PCB design incorporates multiple protection circuits including overcurrent, SWR, and temperature control. The amplifier features various control modes including GND PTT, +13.8V PTT, and RF VOX. Two versions are available: PA70HLI (requiring 100mW input with additional driver) and PA70H (for 3-5W input). The comprehensive documentation includes circuit diagrams, assembly instructions, and performance data showing successful operation from both 100mW and 3.5W input sources.

For radio amateurs and electronics enthusiasts maintaining vintage tube gear, having accurate documentation for tube testers is crucial. Michael Marx, WB0SND, through SND Tube Sales, provides high-quality reproductions of these essential manuals. These aren't mere photocopies; each manual is digitally scanned, cleaned of imperfections, and professionally printed on a _Laserjet 5000_ with heavy card stock covers and plastic comb binding, often making them difficult to distinguish from originals. The catalog includes instruction manuals, schematics, and roll chart supplements for a wide array of classic tube testers. Operators can find documentation for popular models such as the _Hickok 539B/C_, _AVO CT-160_, and _B&K 700_, along with military-grade testers like the _TV-7_ and _USM-118_. Many listings also offer specialized supplements for obsolete or foreign tubes, ensuring comprehensive coverage for diverse tube collections. WB0SND's offerings extend to calibration instructions and data for specific adapters like the _Hickok CA-4_ and _CA-5_, providing critical support for precise tube testing.

This project hereby presented is a complete HAM radio simplex 'smart' repeater, built around a Motorola GM-350/950, Arduino NANO board and a WINBOND audio recording integrated circuit

Decoding NOAA APT weather satellite images is achieved with a homebrew receiver and a Turnstile Cross Dipole antenna, feeding data to a Pentium-3 500MHz PC running Windows XP and the WXTOIMG program. This setup, operated by VU2IIA in Mumbai, India, focuses on capturing and processing signals from NOAA satellites to generate visual weather data. The blog documents the technical aspects of constructing the receiving station, including antenna design and receiver integration. It provides insights into the practical challenges and successes of amateur satellite reception, specifically for Automatic Picture Transmission (APT) signals. Operational details cover the software configuration and image processing workflow necessary to transform raw satellite data into usable weather imagery. The content serves as a practical guide for radio amateurs interested in satellite meteorology.

A Massachusetts Non-Profit 501-C(3) corporation of amateur radio operators chartered in 1978 covering the Connecticut River Valley in Western Massachusetts and Northern Connecticut.

Demonstrates the construction of a custom programming cable for Yaesu VX-7R and VX-5R handheld transceivers, enabling computer interfacing for memory management and frequency coverage adjustments. The resource details a six-transistor circuit design, powered by the computer's RS232 interface, utilizing readily available and inexpensive discrete components. It includes a complete bill of materials, specifying transistors like the _2N2222_ and _2N3906_, diodes, and resistors, along with a matrix board layout for compact assembly within a 75x50x25mm enclosure. The guide provides practical tips for working with matrix board, such as scoring and snapping, track cleaning, and component soldering order. It outlines the specific connection requirements for both the VX-7R (via Yaesu's CT-91 breakout lead with a 2.5mm stereo jack) and the VX-5R (via CT-44 or a four-section jack), detailing signal and ground pinouts. The author successfully tested three circuits, documenting the one with complete two-way communication, allowing users to program their rigs with software like _VX-7 Commander_ and achieve capabilities beyond commercial cables, including band adjustments.