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Electro-Voice Model 664 (EV 664) cardioid microphone, wiring diagram, pictures and data sheet

Low signal, noise-high AC gain preamplifier

Chronicles technical discussions and operational queries related to various Yaesu amateur radio equipment, primarily from February 2004. Topics include troubleshooting the _FT-101E_ -100v circuit, questions about the FT-990, and inquiries regarding the _VX-7R_ service manual. Operators discuss issues like the FT-101's transmit problems, FT-1000D tuning knob behavior, and the FT-897's linear amplifier control. The archive also contains posts about specific components, such as the 2SC2652 RF power transistor, and requests for parts like FT-221R boards. Users share information on CAT interface cables for the FT-1000D and discuss features of handhelds like the VX-2R and VX-7R. This historical snapshot provides insights into common problems and user-driven solutions for Yaesu gear from that era. Several posts offer items for sale, including an FT-208R and an MD-1 desk microphone, alongside requests to buy specific transverters like the FTV-650B.

Draw static response time of an audio system. Originally intended for loudspeakers tests, is also a great tool for looking at microphone equalisation.

Kenwood Ibérica's online presence details their extensive product line, including the NEXEDGE NXDN and DMR digital radio systems, alongside traditional analog offerings. The site categorizes transceivers by mode, such as HF / Todo Modo (All Mode), and portable/mobile VHF/UHF units, catering to various amateur radio operating preferences. This includes specific accessories like batteries, chargers, microphones, and programming cables, essential for maintaining and customizing radio equipment. The Spanish portal also highlights Kenwood's broader electronics portfolio, extending beyond amateur radio. This encompasses car electronics, featuring navigation and multimedia systems, as well as marine receivers and speakers. The product range covers everything from CD and CD-less car receivers to power amplifiers and DashCam/RearCam solutions, demonstrating the brand's diverse market reach. Beyond communications gear, the site presents home audio systems, including all-in-one receivers and portable party speakers. This breadth of offerings underscores Kenwood's long-standing presence in both the consumer electronics and two-way radio sectors, providing a centralized resource for product information and support.

The HotPaw Morse Code Decoder application for macOS processes audio input to transcribe Morse code characters into text. It presents both an audio spectrum graph and a tone amplitude graph, which aid in configuring a narrow band audio filter. Operators can set the audio filter for tone frequencies between 400 and 1600 Hz, optimizing reception for various CW signals. The software offers user-configurable settings, including WPM dot/dash speed detection, a noise threshold level, and the option to use Farnsworth timing for inter-character spacing. The Morse code WPM detection automatically adapts from approximately 8 to 40 WPM, with a lock feature for the estimated speed. A High Speed WPM Mode is available for code speeds ranging from 40 to 80 WPM, catering to faster CW operators. The application's decoding performance is influenced by signal level, signal-to-noise ratio, frequency and WPM stability, keying quality, and proper configuration, with an initial learning phase required for WPM estimation to stabilize. An external microphone or line-in may be necessary for optimal performance on some MacBook models to mitigate fan noise or room reverberations. Version 1.4.4, updated on November 11, 2021, includes compatibility improvements for newer macOS releases. The developer, Ronald Nicholson of HotPaw Productions, does not collect any user data from the application.

A good reference site for antique radio, bakelite paskon plastinc decription, microphones picture and antique radio gallery

Boom Microphone Headsets for use on amateur transceivers- assembled and kit form.

XLT Communications two way radio accessory manufacturer, microphones, headsets, belt clips, earpieces, radio cases

Graph of the frequency response of some of the legendary microphones favoured by radio hams

A simple home made desk microphone project that can be fitted into a small plastic project box

A complete guide to undestand and know how electret condensor microphone elements works by K3DAV

Oakcallsigns.com specializes in custom-crafted oak call signs, presenting various designs for amateur radio shacks. The resource showcases different styles, including standard call sign plaques and options featuring iconic ham radio silhouettes like the _D-104_ microphone. Each item is described with pricing, ranging from $15.00 to **$25.00**, and includes details on shipping and seller reputation. The platform highlights the craftsmanship involved, emphasizing personalized scroll-saw work on each oak piece. It details the seller's positive feedback rating of **99.4%** from over 10,000 transactions, indicating a reliable source for these unique accessories. The site also provides information on the number of units sold for specific designs, such as 2,338 for the standard call sign gift and 554 for the smaller personalized version. This commercial offering focuses on decorative and personalized items for the ham radio enthusiast, distinct from operational equipment. It serves as a direct retail channel for custom shack adornments.

Wiring a Balanced Microphone to the TS-590S Unbalanced Microphone Input

Here a comparison of Kenwood TS-590S used with MC-60A and the oringina dynamic microphone

Operating the _Icom IC-746_ HF/VHF transceiver often presents specific technical questions, and this resource compiles a comprehensive Frequently Asked Questions (FAQ) document in an ASCII text format. It details common inquiries and solutions related to the rig's functionality, accessories, and potential modifications. The content is structured into distinct sections addressing general information, power supplies, antennas, microphones, keyers, amplifiers, TNC integration, and optional IF filters. The FAQ provides practical guidance on topics such as configuring the internal automatic antenna tuning unit (ATU), selecting appropriate power supplies, and understanding microphone pin-outs. It also delves into advanced subjects like computer control via CI-V, wiring for PSK31 operation, and troubleshooting common issues like low S-meter readings on 2m FM or loose tuning shafts. Specific questions cover the installation of optional IF filters, comparing Inrad versus Icom filters, and optimizing filter combinations for various modes. Furthermore, the document outlines various hardware and firmware modifications, including those for increasing monitor volume, replacing LCD driver transistors, and implementing a "poor man's TCXO." It even touches upon untested modifications, such as replacing PIN diodes in the demodulator. The FAQ also lists manual errata and discrepancies, offering a robust knowledge base for IC-746 owners seeking to optimize their station or resolve operational challenges.

Microphone tips for the Icom 706MkIIG

A december 2003 QST article to Build a condenser microphone that will perform like the costly commercial units by KT4QW

CES Wireless Technologies manufacturer of Mobile information Systems including Dispatch and Mapping Software, GPS, AVL, Mobile Data Display Terminals, ANI, CTCSS, and Microphones

This online project guide details the construction of a homebrew boom microphone system. It details the assembly of a microphone shell from a 3/4" PVC pipe section and an end cap, requiring a drilled hole for a snug fit of the electret or condenser mic element. The internal wiring schematic specifies a **2.2 K** resistor and a **47 uF** polar capacitor for signal conditioning, with a circuit diagram provided for integration with IC-706 series transceivers. The guide outlines the use of CAT-5 cable for internal connections, incorporating strain relief at the rear of the mic shell, and an inline 3.5 mm jack to facilitate an external _PTT_ line, designed for a foot-mounted switch. Further construction involves fabricating a microphone shock mount from a 2-inch PVC connector, detailing the creation of four "fingers" and the insertion of screw-eyes for attaching elastic bands, which are twisted 180 degrees for tensioning and vibration isolation. A foam wind screen is also incorporated into the microphone assembly, secured with adhesive. The boom arm itself is repurposed from an articulated architect lamp, with the original lamp assembly converted into a **60 watt** resistive load for testing power sources. Microphone cabling is secured to the boom arm using wire ties, ensuring sufficient slack at hinge points to maintain articulation. The boom base is mounted to a bookshelf, requiring specific positioning to achieve proper microphone placement in front of the operator. Performance evaluation of the microphone system is conducted through on-air audio signal reports from other amateur radio operators. DXZone Focus: Online Project Guide | Boom Microphone Construction | Electret Mic Element | PTT Line

A selection of speakers or headphones for use with amateur radio equipment. Includes an interesting paragraph comparing Dynamic and Electret Condenser Microphones, but also about audio Equalization.

Kenwood TM-201/401 Increased TX Audio, mod for microphone gain

Review of the popular Heil PR-781 mic, connected to an Icom IC-7800 by k3dav

Evaluation of various microphones on-air using an Icom IC-7700 by VA7JW

A keyed piezo beeper, connected to the microphone jack of a HT, appeared feasible as a ready-made MCW generator.

Constructing a digital interface for the Elecraft K2 transceiver, this resource details the "Fat Wire" design by WG4S. It demonstrates how to integrate a sound card for digital modes, outlining specific connections to the K2's microphone jack and internal audio path. The author shares practical insights from his build, including the use of _RG-62_ coax for its flexible braid and the strategic placement of components like the 2.2K resistor and _2N2222_ transistor. The guide provides a breakdown of the interface's internal wiring, specifying connections for AF In (pin 1), AF Out (pin 5), PTT (pin 2), and Ground (pin 7) on the K2's microphone connector. It also covers the external connections to a laptop's headphone and line-in jacks, along with a DB-9 connector for PTT control via _DTR_ or RTS lines. The author notes that his laptop's headphone output level was sufficient for the K2, negating the need for an attenuator. Reflecting on the design, the author, Dan WG4S, acknowledges a later suggestion to house the components directly within the DB-9 shell for a more compact build. This iterative feedback highlights the ongoing evolution of DIY ham radio projects and the community's collaborative spirit in refining designs.

This Microphone comparison article summarizes the test results of two popular ham radio microphones the ElectroVoice RE27 and Heil PR781

AB4BJ optimizing audio settings on the flex 5000A and heil microphones

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.

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.

An homebew microphone boom by W2DTC

Increase microphone gain of the Icom IC-746, and how to add continious-on cooling fan

MorseExpert 1.15 decodes Morse Code audio to text, leveraging algorithms from CW Skimmer for optimal performance on weak, fading signals amidst interference on amateur radio bands. It processes audio from the device's built-in microphone or an external radio receiver via cable, optionally highlighting Ham callsigns and keywords. The application features a waterfall display with a bandwidth of 200-1200 Hz, decodes frequencies between 300-1100 Hz, and supports keying speeds from 12-45 WPM with automatic CW pitch detection. Recent updates include support for Android 15, edge-to-edge mode, improved stability, and a pause decoding button. A premium version offers an ad-free experience and user-selected text colors. Users can switch between General Text mode and Ham Radio QSO mode, which enhances word segmentation and highlights callsigns. The app also includes a frequency lock mode, text selection capabilities for copying, sharing, or saving decoded text, and provides guidance on reducing acoustic echo and constructing an audio attenuator for optimal radio interfacing.

The Kenwood MC60A with preamp, suffers from RF feedback, a search on the web reveals the extent of the problem. This document explain how to fix this problem.

Brugtgrej presents a Danish online classifieds platform specifically for amateur radio operators and electronics enthusiasts. The platform facilitates the buying and selling of used equipment, including transceivers like the Icom IC-7410, various components such as X'TAL FILTER FMT-15A and TRANSISTOR 2SC3019, and accessories like Sadelta microphone capsules and SMA to SMA extenders. Users can post free advertisements for items they wish to sell or acquire, covering categories beyond amateur radio, including antique radios, military radios, and radio tubes. The site lists active advertisements, with 3136 online ads and 167 online users at the time of analysis, indicating a dynamic marketplace. It also features a forum for community interaction, discussing topics like repeater rings on 1297 MHz and FT8 activity. The platform's structure supports both 'Sælges' (for sale) and 'Købes' (wanted) listings across its various sections. Specific items observed include a Miniwatt pentode 4689, various capacitors and coils, and general electronic components, demonstrating the breadth of offerings available to the amateur radio community.

A voice keyer completely integrated into the standard Yaesu MH-31 amateur radio microphone

Mic online calculator , Microphone Dynamic Range Calculator, Microphone Sensitivity Calculator

A Kenwood TM-D710A microphone (Model MC-59) is producing crackling and intermittent, poor audio so John took a peak inside to have a look around.

Review of the Heil PR-781 with a Yaesu FT-950 includes youtube movies and a nice product review

Delta Electronics, Inc. NY USA, family owned and operated selling all varieties of consumer electronics including 10 meter amateur radios, antennas, accessories, microphones, cw transmitters, coax cables and more

This FM wireless mike can transmit voice signals to any FM Radio receiver 100 meters away.

Programming the FT-8800R via the front panel and microphone keypad is not extremely difficult. Already having a list of local repeaters in CHIRP, the addition of a USB cable would allow you to coordinate the memory layout across multiple radios with ease.

Receive and decode SSTV amateur radio SSTV signals with this small and powerfull SSTV decoder app for Android devices. Requires access to microphone.

A Primer On Mics For Ham Radio. Difference between dynamic and condenser microphones, microphone plugs and differences in kind of microphones available on the market

A 15-pin data switch, typically a rotary-knob type designed for DB-25 connectors, forms the basis for this microphone selector project. The resource details the conversion process, which involves replacing the original DB-25 connectors with **RJ-45** or **RJ-12** jacks to accommodate modern amateur radio microphones. It specifically addresses wiring for radios like the Icom IC-706 series (including the IC-7000 and IC-703) and Yaesu transceivers such as the FT-857, FT-897, FT-817, FT-7800, FT-7900, FT-8800, FT-8900, FTM-100, and FTM-400. The design ensures all microphone lines are switched straight through, with separate contacts for external speaker/headphone jacks, allowing simultaneous switching. The project emphasizes the practical application of switching between a headset for net control and a hand mic for rag-chewing without repeatedly plugging and unplugging cables. It highlights modifications to the original concept, such as eliminating a separate PTT jack by integrating PTT into headset cables and building the external speaker cable directly into the selector. The article provides guidance on managing the non-color-coded wiring often found in these data switches by soldering wires one by one from old to new connectors, ensuring correct pin alignment. This approach simplifies the conversion, making it accessible for hams seeking a functional and cost-effective mic switching solution.

Adapting a common PC earphone with microphone to connect to a transceiver via a homemade pre-amplifier, using a simple chip with aprox 10 db gain. Includes a schematic diagram

This article documents the author's latest go-box build for outdoor ham radio operations using a Yaesu FT-891 transceiver. The go-box is constructed from a plastic "50-cal ammo case" and contains various components, including the transceiver, LDG Z11 Pro autotuner, DIY Yaesu FH-2 remote control keypad, and an external battery. The author details the design considerations, the mounting of components inside the box, and addresses issues related to ventilation and cable management. The go-box is geared for CW operations and POTA activations, with further modifications planned for a microphone and DATA jack. This project allows for rugged, environmentally protected outdoor radio operations while maintaining portability.

Mini-Operating Guide includes useful hints on Using the HM-133 Microphone, Basic Operation, Operating through a Repeater, Programming a Memory Channel and Assigning a Memory Channel to a Memory Bank

Complete microphone wiring handbook for most popular radio transceivers provided by Astatic Microphones.

A voice keyer kit available on the marker in two models, BX-184 is the replacement PCB for those who already own an MH-31 microphone. Kit BX-184M includes an MH-31 besides the PCB for those not owning one yet.