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A program to decode morse code (CW) via sound card to text. It can work as narrow-band sound DSP-filter also. No additional hardware is required, you need only receiver and computer with a sound card. It easily integrates with AALog logger. CwGet is a powerful Morse code decoding software for ham radio enthusiasts, featuring a customizable interface with three main windows: spectrum display, oscillogram, and received symbols. It includes auto frequency control, adjustable filters, burst noise rejection, and supports multiple decoding channels. Users can control transceiver frequency via Omni-Rig and record or replay received signals. CwGet also integrates seamlessly with logging software and other applications, allowing data transfer and interaction through DXSOFTEX.DLL. Additional features include manual and automatic threshold adjustments, zoom functionality, and support for various character sets, making it an essential tool for efficient Morse code communication.

The 4-band Fritzel model FD4 is a special version of a Windom antenna. It is a half-wave long on the lowest frequency, and is fed from a coax cable through a transformer inserted in the wire at one-third from one end

Detailed plans of my homebrew receiver. Frequency coverage is from below 300kHz to 30MHz. Pictures, schematics, board layouts, parts lists and more can be found here.

Online radio planning system, allow you to generate accurate radio frequency predictions for anywhere on earth

manufactures and distributes HF, VHF, UHF and SHF equipment covering 10MHz. - 47.0GHz. Our products include: Wireless LAN / WAN Bidirectional Linear Amplifiers, Low Noise Preamplifiers - LNA's, RF Linear Amplifiers, Relays, Transverter Systems, Frequency Translation Systems, Downconverters, Antennas, Parabolic Dishes, Coaxial Cable, Relays, Antenna Switches, Microwave Test equipment, PC controlled Receivers, Microwave Linear Amplifiers including models for Telemetry, Wireless, and CDMA applications.

Macintosh audio spectrum analyzer that allows the user to view live audio in a standard frequency plot, a stereo oscilloscope view and a waterfall display

Free windows program to calculate magnetic loop antenna.This small loop antenna calculator allow to determine capacitance and voltage based on Loop circumference, desired resonant frequency, conductor diameter and the operating power

What is NVIS Near Vertical Incident Skywave. This article on NVIS (Near Vertical Incidence Skywave) explores its role in short-range HF communication, covering 0-200 miles. NVIS utilizes antennas with high radiation angles and frequencies below the ionospheric critical frequency to achieve reliable local contact. He details optimal antennas, like low dipoles, and practical tips for maximizing NVIS performance, emphasizing its advantages such as reduced noise and independent operation without repeaters. However, challenges include frequency sensitivity and the need for appropriate antenna setups at both ends for effective communication.

The terminated tilted, folded dipole T2FD is a little known antenna that performs excellently. Compact in size compared to a half-wave dipole the T2FD provides signal gain, wide frequency coverage, and exceptionally low noise characteristics.

A Portable Low Frequency Antenna Analyzer, For those of us who like to play with antennas on the ham bands, one of the handiest tools to have around the shack is an "antenna analyzer". These gadgets combine a signal generator and standing-wave ratio (SWR) sensor in a small battery-powered unit.

A site for every scanner enthusiast but especially for people living or visiting the lower Vancouver Island Area and Victoria B.C. Canada. This page has pictures with aerial pictures.

The "Tenna Dipper" is a low power antenna analyzer and ATU tuning aid. With this handy accessory, you can determine the 50 Ohm resonance frequency of antennas or you can adjust your antenna tuner for a 50 Ohm match without generating QRM

WorldRadio Article on Petlowany antennas base on this principle: if a length of wire is wound into a spiral-shaped coil and excited by a radio frequency current connected to the innermost portion of the coil, it will then, and only then, exhibit RF characteristics that closely approximate those of a resonant linear wire of the same length

RigResident is a small program for RIG control, which does allow to set and read data of connected tranceiver (frequency, mode etc). RigResident supports more than 70 TRX models from ICOM, KENWOOD, YAESU and Ten-Tec.

The purpose of the APRS-Beacon is to provide simple APRS-compatible position beacons for up to three Objects. It is designed to 'stand alone' and does not monitor other traffic on the frequency. It can use a single-port TNC (in 'native' mode), a single- or dual-port TNC in Kiss mode or the AGW Packet Engine in order to transmit on up to four radio ports.(When running with AGWPE, APRS-Beacon will also work with Windows 2000)

This document serves as a comprehensive guide for amateur radio operators looking to enhance their Yaesu FT-2000 or FT-950 transceivers with pan-adapter capabilities. A pan-adapter is an invaluable tool that allows operators to visualize the frequency spectrum, making it easier to identify signals and improve operational strategies. The guide details the necessary hardware modifications, including the RF Space IF-2000 board and various SDR options, along with their costs and installation procedures. The document caters to operators of varying technical expertise, providing step-by-step instructions and troubleshooting tips. It emphasizes the importance of using a sound card and software like PowerSDR and HRD for optimal functionality. By implementing these modifications, users can monitor multiple frequencies simultaneously, leading to a more productive and enjoyable amateur radio experience. This resource is particularly beneficial for those looking to modernize their equipment and remain competitive in the ever-evolving world of amateur radio.

Design for a very low cost 6-digit frequency counter module using of the shelf components

A page about fascinating Very Low Frequency and natural radio, with lots of streaming audio links from remote receivers. Some experimental stereo pairs around the world.

This simple 30m QRSS beacon is built entirely out of junkbox parts, the only component purchased specifically for this project was the 10,140kHz crystal. Hans Summers' 30m QRSS beacon project emphasizes simplicity and low cost, built almost entirely from reused parts. Key components include a 10,140kHz crystal, a 2N3904 transistor from a broken DVD player, and an ordinary LED used for frequency shift. The oscillator is stabilized in a polystyrene box, with power amplification driven by recycled copper PCB. Output power peaks at 360mW, and a custom 50-ohm dummy load manages heat. Though aesthetically unconventional, the beacon works effectively, fulfilling the project's low cost aim.

Low Cost Frequency Counter, Digital Display and DDS-VFO kits

A simple circuit which will generate a 700 Hz tone into any FM transceiver allowing an amateur to practice CW with another amateur on a 2 meter simplex frequency.

A 160 meter antenna with a base loading coil used to tune the two lower frequency segments of the band.

SignalGen is a free (GPL) Linux (Xwindows GUI-based) utility that generates relatively low frequency signals with the use of a PC sound card. It is an entirely suitable replacement for a hardware signal generator if one doesn't require signals of a frequency higher than about 50 KHz. SignalGen creates any frequency between a fraction of one Hertz and an upper limit determined by your sound card's capabilities.

glfer is a program for reception and transmission of QRSS/DFCW signals. It is composed of two main parts: the spectrogram window, where you can see the spectrum of the received signal vs. time the transmission functions, to emit cw characters at a slow but precisely controlled speed, using the QRSS (slow CW) or DFCW (Dual Frequency CW) modes

This article presents a technical investigation into spurious emissions from the Yaesu FT-847 transceiver when operating on the 70MHz (4-meter) band. The author discovered significant problems with both factory "UK spec" and modified units. Spectrum analysis revealed that when transmitting at 70.2MHz, the radio produces numerous spurious signals, with the most prominent emission at 45.6MHz measuring only 3dB below the fundamental frequency. The study also documents poor power efficiency on 4m (10.3% at 30W output) compared to 6m operation (23.5% at 30W). Tests verified that jumper configurations had no effect on filter selection. The author warns that using these radios on 4m may violate license conditions due to excessive spurious emissions.

Amateur Radio Station owned by Matt Strelow. The station is designed for competition in the multi-operator multi-transmitter category of high-frequency DX contests. Running with 7 towers 6 rotators, 8 beverage listening antennas, and 4 spotting verticals

The Vee Beam antenna project presents a versatile solution for hams, enabling operation across all eight High Frequency bands (80m to 10m) with significant gain on 20m to 10m. This easy-to-construct antenna utilizes two long wires at an angle, enhancing directional performance and minimizing ground losses. With a low visual profile, it is discreet and effective for various applications. The design allows for optimal leg lengths and included angles, ensuring robust performance while maintaining simplicity in construction and operation. The V Beam antenna is an aerial that you can use on all eight High Frequency amateur bands (80, 40, 30, 20, 17, 15, 12 and 10m) with an antenna tuner, and which gives significant gain on the five bands from 20 to 10 meters band.

Leading supplier of low and high frequency electronic filter design products for the design of wireless telecommunications equipment, semiconductors and more

The document provides a detailed guide on modifying an inverted-L antenna to include the 160 meters band. This enhancement allows amateur radio operators to utilize the lower frequency effectively, which is crucial for long-distance communication, especially during the night. The inverted-L design is popular due to its compact size and ease of installation, making it suitable for various environments. By adding top band capabilities, operators can engage in DXing and contesting on 160m, expanding their operational range and opportunities. The guide includes practical tips and considerations for construction, ensuring that the antenna maintains its performance across the extended frequency range. It discusses the necessary adjustments and materials required for the modification, along with potential challenges and solutions. Whether you are a seasoned operator or a beginner, this project can enhance your station's capabilities, allowing for more versatile operations and improved signal quality on the 160m band.

The Icom IC-746 is quite a popular HF/VHF multimode transceiver which has one shortcoming in its standard configuration when used to operate modes requiring good medium-term frequency stability.

It is a application which can be used for troubleshooting CB radio faults, by giving a graphical display of the normal operating frequencies generated by various parts of the CB radios circuits, it can help you identify if a frequency is incorrect or even missing. Another good use for this software is simulating possible frequency expansions, as it allows you to choose any frequency that the PLL is capable of generating, so you can see what the radio will allow you to get !

The document is a technical guide on designing RF filters for radio frequency applications. It covers topics such as interference suppression, band-pass filters, and low pass filters, with a focus on filter design and circuit filters.

This article describes the antenna for Low Frequency Beacon. It originally appeared in the "Lowdown" for Oct. 1999.

Are you suffering from TVI? Then why not try this filter for size. It is a three-stage high-pass filter that blocks low-frequency 50MHz signals while letting through UHF TV.

This modification will allow the MkIIG to transmit on most of the frequencies that it receives on.

The Olivia transmission system is constructed of two layers: the lower, modulation layer is an (almost) classical Multi-Frequency Shift Keying (MFSK) and the higher layer is a Forward Error-Correcting (FEC) code based on Walsh functions.

This was the blogger home page of the Resonant Frequency podcast. Follow the link to get to new web site.

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)

Two Delta-Loops in phase. The purpose of this article is to propose an antenna with a high gain, a high efficiency and a very low price that is easy to build for any frequency.

Project of receive only filters optimized for minimal loss and very high rejection of frequencies below 75% of the filter center frequency by K1TTT

The Burnham Beaches Radio Club frequency counter is a PIC micro controller based frequency counter with LCD readout. It can be used stand alone or the in built offsets allow integration into a receiver

A free small database program for Palm OS that allows you to log ham radio contacts. You can log the call sign, name, date, time and frequency of the contact.

Low power radio modules - supplying rf modules, rf transceivers, radiometrix transmitters receivers, low power radio modules, scada, frequency hopping, 900 mhz, wireless data transmission, data telemetry, gps modules & receivers and more

Low Cost frequency counters and DDS VFO's for QRP and Vintage Radio's. LCD Digital Display, Frequency Counter or DDS VFO

This mod flattens out the ACC2 audio input low frequency response

A receiving loop antenna for low frequency DX Work

iSpectrum is a free spectrum analyzer for MacOS that allows you to display live audio in a standard frequency plot, waterfall display or in a stereo oscilloscope view. Used by ham radio operators, audiofiles, musicians, and Sound Technicians.

T2FD is a 600-900 ohms folded dipole, terminated with resistor. Feed impedance is coupled with 50/600 ohms voltage balun. It is a wide band antenna with rather low SWR over the full designed frequency range: antenna tuner is seldom needed.

W3HH wide-band wire antenna Article in French. The W3HH antenna, also known as the Terminated Folded Dipole (T2FD), is a compact, broadband antenna for amateur radio. It operates at an angle of 20 to 40 degrees and covers frequencies from 3 to 30 MHz. The antenna features a total length of one-third of the wavelength at its lowest frequency and is fed using a 1:4 BALUN transformer for impedance matching. A termination resistor around 390 Ω optimizes performance, making it suitable for various amateur radio applications while being easy to construct and install.

We stock a range of two way PMR446 radios. PMR 446 is a license free frequency, which means that you can communicate for up to 3km (terrain allowing) without any call charges or license requirements. They can be used in most European countries and are ideal for holiday trips.