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Solar activity can aid or hamper HF propagation beyond line-of-sight range, WA1SVF and N6BV answers to questions about Sun influence on radio signals propagation

A synthesized 2.3 GHz Amateur Television (ATV) transmitter design, conceived by Ian G6TVJ, is presented, targeting broadcast-quality video performance on the 13cm band and extending up to 2.6 GHz. The core of the design utilizes a commercial Z-comm Voltage Controlled Oscillator (VCO) that tunes from 2.2-2.7 GHz, providing a +10 dBm output and simplifying RF alignment. This VCO's stability, originally intended for narrowband applications, readily accepts high-frequency video modulation, contributing to the transmitter's robust performance. The exciter stage, incorporating a Mini Circuits VNA 25 MMIC amplifier, boosts the signal to +16dBm, while a Plessey SP4982 prescaler divides the output frequency for the synthesizer. The synthesizer employs a Motorola MC145151 CMOS parallel IC, favored over the common Plessey SP5060 for its superior video modulation characteristics and ease of programming without microprocessors. This choice addresses issues like LF tilt and distorted field syncs often seen with SP5060 designs, particularly when operating through repeaters or over long distances. The MC145151 divides the signal further, enabling precise frequency stepping, with programming handled by EPROMs for channel selection and LED display. The loop filter network, critical for video integrity, was developed through experimentation to prevent the PLL from reacting to video modulation, ensuring a clean transmitted picture. The transmitter incorporates a Down East Microwave commercial power amplifier module, delivering approximately 1.6W output, driven by the exciter through a 3dB attenuator. Construction involves surface-mount SHF components on micro-strip lines etched onto double-sided fiberglass board, housed within a tinplate box. The design boasts no AC coupling in the video path, preserving low-frequency response, a common failing in other ATV transmitters. Performance tests with a 50Hz square wave revealed no LF distortion, and a calibrated "Pulse & Bar" signal showed a near 100% HF response, demonstrating its capability for high-quality ATV transmissions.

A small (FT-817) I.F. radio driving a 100w transverter with a 1db nf front end.

Facilitates logging of amateur radio contacts directly within a web browser, enabling seamless operation across various devices including Windows, macOS, Linux, iOS, and Android. This web-based application stores all log data securely in the cloud, providing accessibility from any internet-connected location. It supports importing existing log data via CSV files, with future plans for _ADIF_ file import, and offers a robust QSL card generation feature, producing print-ready PDF files in standard 148mm x 100mm dimensions. The platform integrates with Japanese government databases to automatically populate callsign-related information such as station location and license issue dates, streamlining data entry. It also assists with JCC/JCG searches for accurate QTH logging. The service leverages SSL encryption for all communications and benefits from security oversight by certified information security professionals. Users can register using email/password or existing Facebook/Google accounts, and the beta version is currently available for free. The system has processed over **5,297,881** logs, with **28,369** logs recorded in the past 24 hours.

Article about an end-fed anntenna for the 17 and 12 WARC Bands. 30 meters is not included in this project. This antenna includes a 14 windings unun impedance transformer using a FT-140-43 ferrite toroid, that should be enought for a 100W PEP.

Make 1000 two-way contacts with any station on any satellite

A nice review of the Acom 1000 HF and 6 meter RFpower amplifier by Acom in Dutch and with online google translation available. Includes pictures and notes of the popular amplifier by Acom.

Freeband modification for the Yaesu FT-100

The OZ1CX center-loaded mobile antenna project details the construction of a compact **80-meter** antenna, specifically designed for mobile, portable, and stationary operations. It features a loading coil wound on a 50 mm PVC pipe with 1.5 mm copper wire, comprising 100 turns over 150 mm length, resulting in an inductance of 150 µH. The design incorporates a 1.5-meter whip and a 1.5-meter base section, with the coil positioned at the center for optimal performance on the 3.5 MHz band. Performance measurements indicate a **VSWR** of 1:1.2 at 3.7 MHz when mounted on a vehicle, achieving a bandwidth of 30 kHz for VSWR below 1:2. The antenna's efficiency is compared to a full-size dipole, showing a signal strength reduction of 3-4 S-units, which is typical for compact mobile HF antennas. Practical application notes cover tuning adjustments by varying the whip length and coil tap points, emphasizing the importance of a good ground plane for effective operation.

IARU NCDXF Beacon in Sri Lanka 4S7B working on 14.100, 18.110, 21.150, 24.930, and 28.200

Technical specifications and details of the Yaesu FL-2100B HF Power Amplifier

100-watt UHF repeater (444.500+ PL100) and a 6-meter repeater (53.68- PL114.8) are owned and maintained by South County ARES to support emergency communications for Belmont, East Palo Alto, Foster City, Menlo Park/Atherton, Redwood City, San Carlos, San Mateo, and Woodside/Portola Valley. The organization emphasizes training, including weekly nets and practice sessions, to improve message passing accuracy and brevity, crucial skills for **emergency communication**. Resources like the San Mateo County Sheriff's Office Ham Radio Frequency Plan Recommendation and **Chirp-compatible CSV files** for Baofeng radios are provided. Participation in community events is encouraged to build skills and connections among members. The group operates without collecting dues, relying on donations and member contributions of time and expertise. Training pages are available for new hams and those seeking license upgrades, along with a "Tips for New Hams" section. The site also features a monthly calendar of events, including board meetings, general meetings, and hospital nets, alongside a newsletter, the "South County Communicator," and various operational documents like the Net Control Manual and SCARES Handbook.

Adding a full power output 12 meter band capability to the Yaesu FL-2100 despite of 10 meter.

Connecting a Yaesu MD-100 dynamic desktop mic to the Kenwood TS-850

The Lakeshore Repeater Association (KR9RK) operates a **VHF** 2-meter repeater on 147.270 MHz, utilizing a +600 kHz offset and a 100 Hz PL tone, serving the Raymond, Wisconsin area. The organization provides access to monthly newsletters, with recent editions including March 2026, February 2026, and January 2026, detailing club activities and operational updates. A Google Docs link is provided for newsletters with functional embedded links, addressing issues with PDF versions. The association's Megacycle Group is actively constructing a **DX Contest** level HF network, designed for remote accessibility. This initiative aims to provide members with a competitive edge in global DX hunts by enabling worldwide access to the station's radios. Additionally, the Lakeshore Radio Association is commemorating its 50th anniversary with a special event station, K5O, inviting all members to participate in on-air operations.

Evaluates the **LDG Z100 autotuner**, a device designed to automatically match antenna impedance for optimal transmission efficiency. The review discusses its performance in comparison to the MFJ-902, noting that while the Z100 is a reliable autotuner, it does not match the range of impedances that the MFJ-902 can handle. The Z100 is suitable for operators seeking a 100-watt autotuner that covers HF bands, providing a practical solution for those who require automatic tuning without manual adjustments. The review highlights the Z100's operational context, focusing on its use in HF bands and its practical application in amateur radio setups. While it offers a straightforward tuning process, the Z100's limitations in impedance matching are noted, making it less versatile than some competitors. This comparison provides valuable insights for operators considering an upgrade or replacement for their current autotuner. The Z100's performance is positioned within the broader market of autotuners, offering a clear perspective on its strengths and weaknesses in real-world amateur radio operations.

The problem originates by improper TXOUT-to-RF timing (RF transmission exists still after a TX-EN prohibition), combined by too long decay of their CW pulses.

Yaesu FT-100D Active Interface for the Codan 9350 and Comet SB-15 Antennas

Amateur radio antennas manufacturer based in Italy. Produces HF end-fed, dipoles, and other wire antenna types, mono band and multi band antennas.

The WB5RVZ Genesis Radio G40 build log documents the construction of a 5W QRP 40m SDR transceiver kit, detailing each phase of assembly from power supply to RF filtering. It provides specific component lists, parts placement diagrams, and testing procedures for stages like the local oscillator, Tayloe detector, and RX op-amps. The resource highlights discrepancies between documentation versions and offers practical advice for builders, including a "virtual build" approach to preemptively address potential ambiguities in component identification and placement. It also addresses a specific "VK6IC Fix" for early board revisions, involving trace cuts and jumper wires for improved performance. The build log presents measured voltages and expected current consumption for various stages, such as the 4.9-5.0 Vdc on the 5V rail and under 100mA for RX current. It outlines critical adjustments like image rejection tuning, a common procedure for direct conversion receivers. The resource also includes practical tips for handling components like the 2N3866 transistor and its heatsink, emphasizing pre-assembly. It details the winding of two 1.45 uH toroidal inductors on T50-6 cores with 17 turns of #20 AWG wire, crucial for the RF path.

Over 100 trained amateur radio operators comprise the New York City Amateur Radio Emergency Communications Service (_NYC-ARECS_), an auxiliary communications service dedicated to providing vital radio links during local, regional, or national civil emergencies. This organization supports governments, civil-preparedness, and relief agencies in situations such as power failures, explosions, fires, floods, earthquakes, or terrorist activities. Their operational readiness is critical for maintaining communications when conventional infrastructure fails, leveraging the resilience and adaptability of amateur radio. NYC-ARECS actively participates in the NYC Office of Emergency Management (_OEM_) Partners in Preparedness program and is a member of DHS FEMA's National Preparedness Coalition, demonstrating its integration into broader emergency response frameworks. The group's activities include regular training, maintaining operational readiness, and deploying communication assets across the five boroughs of New York City. Their efforts ensure robust, independent communication channels are available to support disaster relief and public safety operations.

ACOM 1000 160-6m amplifier specifications and features

The IZ3MEZ Web DX Cluster presents real-time amateur radio DX spots across 20 distinct frequency bands, spanning from **LF (2190m)** at 135.7 kHz up to **SHF (QO-100)** at 10499 MHz. It displays the DX callsign, frequency, DXCC entity, spotter callsign, and spotter DXCC entity, along with any accompanying comments. The cluster also lists various operating modes such as CW, RTTY, FT8, FT4, FT2, PSK, and SSTV, and supports special operating activities like QRP/P and specific award programs including IOTA, POTA, SOTA, WCA, and JOTA. The cluster's interface provides a dynamic feed of the latest 50 spots, continuously updated with precise timestamps. It offers direct **Telnet protocol** access for users preferring a command-line interface, with configuration instructions provided. The resource also integrates with other spotting networks like RBN and PSK Reporter, enhancing its utility for DXers and contesters seeking propagation information and activity monitoring across a broad spectrum of amateur radio frequencies.

The Matanuska Amateur Radio Association (M.A.R.A.) is a general interest amateur radio club, with approximately 100 members, our members are involved in every aspect of amateur radio.

How to correct keyclick problem in ft1000 and ft1000d radios.

The Kenwood TS-870S HF transceiver features two state-of-the-art 24-bit 20 MIPS DSP chips, providing over 100dB out-of-passband attenuation and CW bandwidth adjustable to 50 Hz. It operates across 160-10 meters with 100 watts output, incorporating digital filtering, a beat canceller, and 100 memory channels. The radio also includes a transmit equalizer, RX antenna input, and a K1 Logic Keyer, enhancing signal processing and operational flexibility for amateur radio operators. Advanced capabilities include IF stage DSP, dual noise reduction, and an auto notch filter, all contributing to superior signal reception and clarity. The TS-870S offers a variable AGC, voice equalizer, and an RS-232C port for computer control, with Windows™ software supplied. Its built-in automatic antenna tuner functions on all bands for both transmit and receive modes, streamlining station setup and operation. Available accessories such as the DRU-3A digital recording unit, SO-2 high stability crystal oscillator, and VS-2 voice synthesizer option further extend the transceiver's utility. The unit requires 13.8 VDC at 20.5 Amps and is supplied with an MC-43S hand microphone, making it a comprehensive station component.

Info on 2013 Icom recall for IC-7100 for touchscreen replacement and N-Connector substitution with SO-239 by PD0AC

Demonstrates the fundamental principles for connecting a personal computer to a ham radio transceiver, specifically for utilizing sound card-based digital mode software like those in the MM Hamsoft suite. It details the basic hardware setup, emphasizing the use of shielded leads and proper audio routing from the radio's output to the sound card's input, and from the sound card's output to the radio's microphone or data input. The resource highlights the critical need for transmit attenuation, suggesting a 100:1 voltage divider to prevent overdriving the transmitter's audio stage, and mentions the optional addition of ferrite beads and decoupling capacitors for RFI mitigation. The guide also points to external resources for more detailed pin-outs and interface schematics, such as a specific QSL.net page, and recommends consulting the help files within MM Hamsoft programs for interfacing specifics. It underscores that while the process is straightforward, understanding the audio level management and proper cabling is key to successful operation. The author, VE5KC, provides practical advice drawn from common issues encountered by operators setting up digital mode stations.

Fifty-three digital modes, including PSK31, RTTY, and JT65, are explored in this resource, providing detailed descriptions of their underlying technologies and typical use cases. It covers error correction methods like ARQ in PACTOR and FEC in JT65, alongside modulation schemes such as FSK and PSK. The content highlights the evolution of digital communication from traditional TNC-based systems to modern sound card implementations, emphasizing the role of personal computers in advancing these modes. Specific modes like AMTOR, PACTOR, and G-TOR are discussed, noting their baud rates and error correction capabilities. For instance, AMTOR operates at 100 baud, while PACTOR offers 200 baud with Huffman compression. The article also delves into newer modes like MFSK16, which uses 16 tones and continuous Forward Error Correction, and Olivia, capable of decoding signals 10-14 dB below the noise floor. Each mode's bandwidth, speed, and resilience to propagation challenges are examined, such as MT63's 1 KHz bandwidth and 100 WPM rate, or Hellschreiber's 75 Hz bandwidth and 35 WPM text rate. The resource also lists predominant USA HF digital frequencies for bands like 160, 80, and 40 meters, specifying segments for PSK31, RTTY, SSTV, and Packet. It includes links to freeware and shareware sound card software such as Digipan, FLDigi, and MixW, enabling amateurs to experiment with these modes.

We are a group of over 100 people dedicated to Amateur Radio.

10 meter 28.286 mhz 100 milliwatt Beacon

HF/50 MHz 100W All Mode Transceiver. The FT-891 provides stable 100 W (25 W AM) high power output

Official aprs.fi iOS app, immediate real-time visibility to APRS traffic near you and around the world.

M5AML - SSTV, Aerials (antennas), SSTV, Rallies, UK prefixes

The 2200-meter band (135.7-137.8 kHz) presents unique challenges for amateur radio operators due to its narrow 2.1 kHz bandwidth, low signal levels, and high noise. W1TAG explores various transmission modes suited for this demanding environment, highlighting that traditional voice modes like SSB and AM are impractical. Plain old CW serves as the baseline, demonstrating effectiveness across different modes, though signal-to-noise ratio (SNR) significantly limits practical speeds. The article notes that reducing CW speed below 5 WPM can improve copy, especially with computer-aided spectrum analysis software capable of decoding signals too weak for human ear reception. QRSS, or "CW sent slowly enough that speeds are best expressed in seconds per dot," is a key mode for LF work, with examples ranging from 3 seconds/dot to extreme 240 seconds/dot transmissions. _Argo_ by I2PHD is mentioned as a simple program for QRSS, enabling reception of signals like BRO, a Part 15 beacon, at a distance of **1100 miles**. Other modes discussed include Dual Frequency CW (DFCW), which uses frequency shifts to distinguish dots and dashes, and Binary Phase Shift Keying (BPSK), a phase modulation technique employing 0 to 180-degree phase flips. WOLF (Weak-signal Operation on Low Frequency), a specialized BPSK form by KK7KA, encodes 15-character messages into 960-bit packages, taking 96 seconds to transmit, and has demonstrated successful reception over **672 seconds** for a message from a 1-watt beacon. Further modes include PSK, FSK variations like JASON and MSK, and graphical modes such as Hellschreiber and Chirped Hell. The article concludes with a practical chart comparing the time required to send a simple message like "WD2XES FN42CH " across these diverse LF modes, offering valuable insights for operators planning contacts on the low bands.

Details the Big Thunder Amateur Radio Club (BTARC), a long-standing amateur radio organization based in Boone County, Illinois, established in 1962. It covers the club's mission to enhance the skills of local hams, promote radio knowledge, and foster social interaction among operators. The resource outlines BTARC's commitment to community service, including emergency communications support through RACES, and its active participation in events like Field Day, fox hunts, and public service communications for local races. Explains the club's history, including the establishment of its first repeater in the 1970s by members WD9JGH, Mike George, K9ORU, and Claude Horsman, WB9PMM, using a VHF Engineering kit and a Sinclair duplexer. It provides specifications for two club-maintained FM repeaters: a 2-meter repeater on 147.375 MHz (+600 KHz shift, 100.0 Hz PL tone) and a 70-cm repeater on 442.825 MHz (+5 MHz shift, 114.8 Hz PL tone). The club hosts a weekly 2-meter net on Sundays at 7:00 PM local time and holds monthly meetings on the second Thursday at the Spring Township Building in Belvidere, IL.

Building equipment for AMSAT P4A geostationary Es'hail-2 Quatar OSCAR 100 Satellite

The Kenwood TS-450S is a formidable transceiver covering 160 through 10 meters including the WARC bands with 100 watts input

Constructing a high-performance RF spectrum analyzer up to 1000 MHz requires careful attention to component selection, shielding, and circuit isolation. This resource details a project that improves upon the _Spectrum Analyzer for the Radio Amateur_ design by Wes Hayward (W7ZOI) and Terry White (K7TAU), incorporating ideas from Scotty Sprowls' project, particularly his 1013.3 MHz IF bandpass cavity filter. The analyzer utilizes a Mini-Circuits SRA-11 mixer with a sweeping local oscillator from 1013 to 2013 MHz, feeding into a 4-pole copper pipe cavity filter. The design employs a second SRA-11 mixer with a fixed 1024 MHz LO to produce a 10.7 MHz final IF. This signal then passes through narrowband resolution filters and is processed by Analog Devices AD603 and AD8307 ICs for IF amplification and logarithmic detection, driving an oscilloscope in X/Y mode. The project emphasizes modular construction, using salvaged components and double-sided FR4 material for PCBs, with critical notes on minimizing spurious images through effective shielding and proper voltage regulation for each module. Key components include a Z-Communications V585ME48 VCO for the first LO and a Z-Comm V583ME01 VCO controlled by a Motorola MC145151 PLL for the second LO. An optional Hittite HMC307 step attenuator and K&L 5L121-1000/T5000-O/O low-pass filter manage RF input. Tuning procedures for the 10.7 MHz IF resolution filter are also detailed, showing before-and-after spectrum views.

DSP-100 Hi-Fi TX and RX Mods for the TS-850S by KA0KA

Reviews of the Yaesu FL-2100 series power amplifier at eham

The **LDG Z100 Autotuner** review by GW6ITJ details the unit's practical application and performance in a ham shack environment. Initially acquired to replace an MFJ-902, the Z100 is noted for its ease of use, though the author observes it doesn't quite match the impedance range of the older MFJ unit. This hands-on assessment provides a real-world perspective on its capabilities for 100-watt operation across the HF bands. GW6ITJ specifically mentions the Z100's suitability for 3.5 MHz and higher frequencies, indicating its utility for common HF operations. The review focuses on user experience rather than technical specifications, directing readers to the LDG website for detailed data and manuals. This approach highlights the tuner's operational characteristics from a user's perspective. The author's experience with the Z100 suggests it's a reliable choice for general amateur radio use, particularly for those seeking a straightforward autotuner. The comparison to the MFJ-902 offers a valuable benchmark for hams considering a similar upgrade or new acquisition, emphasizing practical differences in impedance matching.

The _Touch CPO_ circuit offers a unique method for Morse Code practice, eliminating the need for a physical key. It leverages the versatile IC555 timer, configured as an astable multivibrator, to generate an audio tone. Users can adjust the tone's frequency by manipulating a 100 K variable resistor connected between pins 7 and 6 of the IC555, providing flexibility in the practice experience. Volume control is achieved via a 10 K variable resistor, while a 1 K Ohms preset at pin 4 of the IC555 allows for fine-tuning the touch plate's sensitivity. The design connects the touch plate to the base of a BC147B transistor, a configuration noted for its flexibility regarding the length of wire between the transistor and the touch plate. The author's prototype successfully used a 9 cm wire with a 3 x 6 cm aluminum plate. This project also suggests an alternative application as a touch-operated doorbell, demonstrating the circuit's adaptability. The design emphasizes simplicity and ease of construction, making it accessible for hams interested in DIY electronics.

How to convert the ICOM VHD base station IC-275D to 275H 100W 144-148Mhz

Six Steps for Programming your IC-2100H from the front panel of radio. Using these steps you should have no trouble entering either simplex or repeater frequencies and saving them.

KA0KA ESSB with the Kenwood TS-850/DSP-100 project

A Rig control CAT interface schematic suitable for both the Yaesu FT-817 and FT-100 transceivers.

The contest takes place the first full weekend of May (from 1800Z on Saturday May 5 to 0400Z Sunday May 6, and from 1100Z to 2100Z Sunday May 6). A total of 20 hours contesting!

This generator requires 100volts supply at 5mA. A 0 -5 mA meter inserted at J1 measures the crystal current.

Constructing a basic multimeter involves integrating a 0-1mA meter movement with various shunts and multipliers, selected via a switch, to create a versatile instrument capable of measuring DC volts, current, and resistance. The design outlines two main units: a primary unit handling six DC current ranges up to 1 amp and eight DC voltage ranges up to 1000 volts, alongside an internal battery for an ohms range up to 200,000 ohms. This approach allows for a practical, hands-on understanding of meter operation. An add-on unit further extends the multimeter's capabilities, incorporating a meter rectifier and switched series resistors to provide four AC voltage ranges up to 100 volts. Additional shunt and series resistors, designated Ra and Rb, are included to expand the instrument's range to 10A and 5kV, demonstrating how modular design can enhance functionality. When this add-on is in use, the main instrument is set to measure 1mA FSD, connecting via specific lugs. Component selection emphasizes precision, with 1% tolerance high stability resistors for series elements and Eureka resistance wire for shunts. The design specifies values calculated for a meter with 60 ohms internal resistance, noting that these would require modification for different meter characteristics. Experimental adjustment of shunt values is recommended to ensure accurate readings against a calibrated reference meter, reinforcing practical calibration techniques.