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

How to program Baofeng handheld transceiver with satellite frequencies, and how to get alerts when satellites are visible by using a smartphone app. A beginners guide to work satellites with a common VHF handheld radio.

Gold Line, a manufacturer, provides a range of professional audio test and analysis equipment, including specific products like the **ZM1 Impedance Meter**, which is relevant for amateur radio operators needing to characterize antenna systems. The site also lists various noise sources and microphones, such as the TEF04 Mic, indicating a focus on audio signal integrity and measurement. The resource details contact information for repairs, calibration, quotations for specific products like the ZM1 and ZM1P, and technical support, with distinct email addresses and phone numbers provided for each function. This structured contact approach facilitates direct engagement with the appropriate department for specific inquiries. Operational changes effective March 1, 2019, are noted, directing users to VLDESIGN for repair and calibration, and to Partha Chen for ZM1/ZM1P quotations. Louis Pittsley is designated for technical support, with a general inquiry phone number also available, outlining the company's support infrastructure.

For a lightweight portable station, all you need is a handheld transceiver, a tiny packet TNC, and an Android smartphone.

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

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.

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

Manufacturer of Repeater Controllers, Repeater Tone Panels and Telephone Interconnect.

This is a neat little adapter that allows the use of a cell phone type Headset with your Amateur Radio.

DTMF Remote Controls, DTMF tone generators and broadcasting products, remote broadcasting via cell phone, cell phone mixer and remote phone keypad

Manufacture remote control interfaces to manage several kind of ham radio transceivers, Antenna rotators and antenna switches. Control can be done using smartphone Apps or from Computers.

ARRL page dedicated to AM operations

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

Thanks to the popularity of cell phones, laptops and other personal electronic devices, the battery industry has been market-driven to produce higher capacity batteries in lighter weights than previously possible with yesterday's chemistries.As a result, a wide variety of battery types are available to the outdoor QRP operator.

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

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 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

Helps you study for the Ham Radio & FCC GROL exams. Often times, test questions are worded in ways; that fool you. RadioTelephone Tutor drills on missed questions, till you know the answers backwards and forwards. Can take entire question pools in straight, or random order. Creates a practice test; which represents what you would be given in a real exam.

The Horn reflector antenna at Bell Telephone Laboratories

JAS-2 is prepared to succeed the communication of JAS-1b launched in February 1990 and still working. So JAS-2 is also capable of phone,CW and packet BBS.

A free repeater database app for iPhone and iPad includes repeaters from 35 different countries and is available in 5 languages

This project fills the need for a 706 mic/headphone/PTT adapter.

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

Free pdf book on Nicola Tesla. He is the true unsung prophet of the electric age; without whom our radio, auto ignition, telephone, alternating current power generation and transmission, radio and television would all have been impossible

Decode DTMF from your iPhone. Hold your smartphone close to a DTMF source and this app will decode the numbers being dialled.

G8EPR pye telecoms museum incorporating.. emeregency services & radiotelephone museum of great britain

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.

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

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.

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.

Weak Signal Audio 160m, choosing a headphone for weak signals reception

Use your Smartphone as an Oscilloscope to visialize signals from 150 Hz to 15kHz and as a Signal Generator to generate sinusoidal, square and triangular signals up to 15kHz

Presents _Beam Quest_, the official Japanese distributor for _SteppIR_ antennas, detailing their product lineup and services. The site showcases various _SteppIR_ Yagi models, including the _Dream Beam_ series (DB42, DB36, DB18E, DB11) with configurations from two to four elements, alongside the _Big IR_ and _Small IR_ vertical antennas. It also lists accessories such as TX/RX and PC interfaces, essential for integrating these advanced antenna systems into a ham shack. Operators often seek out _SteppIR_ antennas for their dynamically adjustable element lengths, which allow for optimization across multiple bands, a significant advantage for DXing and contesting. This adaptability contrasts sharply with fixed-element Yagis, providing a distinct edge in varying band conditions. The resource provides contact information, including email and phone numbers, for inquiries and support regarding _SteppIR_ products within Japan, serving as a direct point of contact for sales and technical assistance.

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

It is possible to add a very small Bluetooth transmitter to the 3.5mm headphone jack and then use a pair of Bluetooth headphones around the shack. In this article Author provides some tips on choosing the proper Bluetooth interface.

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.

Modem Telephone Super Filters For HF and AM Radio Interference.

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

Ham radio transmissions can interfere with television reception. This is called television interference, or ham radio TVI. Consumer adoption of cable television has significantly reduced ham radio TVI. But the introduction of IPTV, or television over phone systems, has brought ham radio TVI back, often with a vengeance. Here's why

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

Vox recorder is activated by voice and sounds exceeding a threshold. It saves for every record a .caf file that you can play, delete or send by email. Useful for surveillance records, hamradio scanners, and many many other applications. You'll be surprised to hear what happens in an all night using Vox recorder.

Amateur radio speakers for modern amateur radio transceivers

Interface board was for connecting Yaesu FT-817ND transceiver to Android phone or tablet. The board was developed for experimenting with RTTY, SSTV and other digital modes using DroidRTTY, DroidSSTV and other software on an Android phone.

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.

Australian antenna manufacturer, Mobile 1 CB Radio Antennas, Mobile Phone Antennas 3G, NextG, EDGE Digital Radio & TV Antennas Broadcast Band Antennas Airband Antennas Amateur Band Antennas Scanner Antennas Commercial Antennas

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