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Welcome to scannewbedford.com. This site was built for people who would like to hear a live broadcast of New Bedford Massachusetts public services. There are also a few frequencies from other local towns such as Dartmouth, and Fairhaven being broadcasted on our live audio feed. The web site is free for everyone to use and pass along to another friend. Thank you and enjoy the Scan New Bedford Live Scanner Audio Broadcast of New Bedford`s Police, Fire, and EMS.

Information and digital audio samples of various modem modulation types

Design guidelines for Op Amp audio preamplifier circuits by Mike Martell N1HFX

Frequencies, links for scanners, email lists, online audio and more for Maryland, DC, and parts of Delaware and Virginia

Audio and waterfall images of some sounds found on the RF spectrum

A re-usable control & computing platform for antenna measurement, PSK31 digital modems, audio filtering, signal source & VFO, memory keyer by AMQRP

Operating on 160 meters from a city lot is always a challenge. Here's how K9YC does it.

Minimal interface circuits for receiver and transmitter audio, also for PSK31

This online guide details the microphone pinout for the Kenwood TR-7950 transceiver, specifically addressing the wiring configuration for a dynamic mobile microphone with a **500 Ohm** impedance. It provides a pin-by-pin breakdown for the 6-pin microphone connector, identifying the function of each active pin. The resource specifies that Pin #1 is for the microphone audio (white wire), Pin #2 controls the _PTT_ (black wire), Pin #3 activates the memory down function (blue wire), and Pin #4 controls the memory up function (red wire). Pin #6 is designated as the ground connection, while Pin #5 remains unused in this configuration. The document focuses on the physical wiring necessary to restore microphone functionality to the Kenwood TR-7950, a transceiver capable of **45 watts** output on the _2m band_. It directly addresses the technical challenge of re-establishing correct electrical connections after microphone wires have been disconnected from the connector. The information facilitates proper microphone operation for simplex QSOs and other voice communications. DXZone Focus: Online Guide | Microphone Pinout | Kenwood TR-7950 | PTT Wiring

ARRL Audio News contains highlights taken from the League's weekly publication, The ARRL Letter. ARRL Audio News is available via internet in mp3.

LIVE 911 audio of the Chicago Fire Department North & South channels.

Shure incorporated, microphones and audio electronics

Need to interface both a TNC and the computer soundcard? This is a ICOM 756PRO ACC1 audio/keying/FSK interface by WA0SXV

Live audio feed from Denver Colorado Police

This circuit consists of microphone amplifier and a high pass filter. Suitable to improve signal readability.

Adjusting audio output of your soundcard to obtain a perfect PSK signal from your transmission. A project to help you tuning your PSK31 emission.

Live streaming audio of the K7ICU repeater

Demonstrates a practical approach to improving Morse code proficiency through a curated selection of audio files. The resource offers downloadable MP3 files designed for CW practice, catering to operators aiming to increase their copying speed and accuracy. Content includes both standard words and specific amateur radio callsign groups, which are crucial for effective on-air communication. The files are organized to facilitate progressive learning, allowing users to select material appropriate for their current skill level. This collection supports the development of essential CW operating skills, particularly for those preparing for contests, DXing, or general ragchewing on HF bands. The _ON6ZQ_ site, maintained by _Christophe David_, also features information on his _Reverse Beacon Network_ skimmer and _SOTA2APRS_ feed, indicating a strong focus on active operating modes and digital integration.

Manufacturer of led digital clocks, digital timers, countdown clocks, electronic kits, audio switches, binary clock, telegraph keys, and cool gadgets.

FreqTweak is a tool for FFT-based realtime audio spectral manipulation and display for Linux, offering various algorithms for audio processing in the frequency domain and an interactive GUI. It provides high-resolution spectral displays like scrolling-raster spectrograms and energy vs frequency plots.

Understanding and solving RF interference problems using ferrite

Audio setting and improvements for Yaesu FT-2000 by k6jrf

Germany's International Broadcasting Station with links to numerous pages in multiple languages containing program schedules, and live audio feeds.

Lage collection of 6 Meters and 2 meters QSOs, recorded in real audio format by OE3MWS

Antique radios and audio sold to collectors and dealers

Shortwave Monitoring Station in Berlin: DX news, HF propagation, greyline, DRM news, QSL gallery, audio recordings and more

Maker of QRP Kits, QRP CW receiver and transmitters, audio CW Filters, antenna tuners, dummy loads, and morse code practice oscillator

For amateur radio operators engaged in **radio direction finding** (RDF) and **transmitter hunting** (T-hunting) activities, this resource provides a catalog of printed circuit boards (PCBs) for constructing various DF and foxhunt-related projects. The offerings include PCBs for 80-meter fox transmitters and receivers, UHF fox transmitters with audio recording capabilities, and several designs for general-purpose radio direction finders. Specific projects like the "Simple 80M ATX-80 Transmitter" and the "N0GSG DSP Radio Direction Finder" are listed, along with attenuator boxes and specialized components for Doppler DF systems. The catalog details PCBs for projects published in prominent amateur radio magazines such as *73's*, *CQ*, *QST*, and *PE*, indicating their origin and design pedigree. For instance, the "Montreal Fox Controller" is sourced from the *Homing-In* column by Joe Moell, K0OV. The resource also lists components for advanced Doppler DF systems, including main boards, LED display boards, and antenna switch boards, with options for programmed PIC microcontrollers. Pricing for each PCB is provided, allowing hams to acquire the necessary components for their DIY RDF endeavors.

Hidden transmitter hunting, often called fox hunting or Amateur Radio Direction Finding (_ARDF_), presents a unique challenge for radio amateurs. This resource details the _PicCon_ controller, a specialized device designed to automate the transmission of signals for such events. It integrates with a standard radio transceiver, functioning similarly to a packet radio TNC, by controlling the Push-To-Talk (PTT) line and injecting audio tones or modulated CW Morse code into the microphone input. The _PicCon_ unit is field-programmable using DTMF tones received via the radio, storing all settings in EEPROM for power-off retention. Its compact design and low power consumption (a few milliamps from a 7-35VDC source) make it suitable for remote deployment. An onboard LED indicates operational status, and a push-button allows manual start/stop of transmissions without DTMF. Typically supplied as a kit, _PicCon_ includes a PCB, components, and a comprehensive manual (available in HTML, RTF, and PDF formats). The kit provides a six-conductor interface cable, but users must supply radio and power plugs due to varied configurations. Byon, _N6BG_, developed this controller, which is available from the Byonics website.

Yaesu FT857D No TX Audio, video on reparing and yaesu Mic modification, with audio improvements for SSB and FM

Rutherford County Sheriff and Fire Live Scanner Audio Feed on RadioReference.com

Beacons recorded audio files by kl7fdq

Distributor of Sovtek, other current production vacuum tubes, and NOS tubes. Distributor of electronic parts for audio and musical instrument amplifiers. Manufacturer/ Distributor of Electro-harmonix effects.

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.

Live streaming audio from Redding police, Redding fire, hospitals, ambulances, Fish and Game, Anderson police, search & rescue, CHP, and fire districts. Redding Californa.

EchoLink and IRLP Internet Radio Linking Project Node's, Hurricane Watch Audio Feed's and Info, Live Scanner/Other Feed's from the USA, Local Ham Frequencies, Online Receiver's, Shoutcast Live Audio Feed's from the USA, Southern California Frequencies and more

DarkIce is a live audio streamer. It records audio from an audio interface (e.g. sound card), encodes it and sends it to a streaming server. Works on Linux and MacOSX

VE2ZAZ and distorted audio in SSB on some models prior 2006

A set of utilities for the SSTV enthusiasts. SSTV signal generator, to generate SSTV audio signals from a bitmap. SSTV Signal Viewer to demodulate SSTV signals, anf SSTV Image Denoiser to removes noise from the pictures. By VE3NEA.

Audio files to help identify rf noise (rfi). Identify the RFI that interferes with your reception. RFI Noise identification.

Collection of audio clips of foreign radio stations, with identification announcements in various languages, signature tunes and jingles, and of course interval signals

UK dealer for pmr audio accessories, batteries and cases, audio accessories and airwave tetra products

Otto engineering is comprised of two divisions otto controls and otto communications. otto controls designs and manufactures a full line of switches and grips used in heavy equipment, aerospace, marine, medical and other demanding applications. otto communications designs and manufactures audio accessories for two-way radios used in public safety, police, fire, retail, hospitality manufacturing and other markets.

The Elecraft K2 transceiver requires specific modifications for optimal soundcard digital mode operation, particularly for PSK31. The original article, circa 2001, details initial challenges with manual PTT and speech compression settings. A key modification involves adding headphone audio and a compression disable signal to the K2's microphone jack, utilizing pins 4 and 5. The **COMP0** signal, active low, is shorted to ground via a non-inverting open collector switch circuit, comprising two resistors and two transistors, mounted on the SSB board near U3. This circuit provides effective control of an analog signal line with good noise immunity. The switchbox itself repurposes a computer COM port switch, using only two of its original connectors and four of the nine poles. It integrates a microphone preamplifier, a PTT circuit built with 'flying leads' construction, and RCA jacks for soundcard connections. A trimpot adjusts the audio drive to the K2. The central DB9 connector links to the K2's mic connector via a shielded RS232 serial cable, ensuring proper grounding and signal routing. An external footswitch PTT jack is also included. Further enhancements include a **noise-canceling microphone** preamp based on a QST December 2000 article, adapted for Heil mic elements. This preamp, built with pseudo-Manhattan style construction, provides a gain of approximately 2 by changing emitter resistors (R9 and R16) from 680 ohms to 330 ohms. A 10-ohm series resistor and 47 µF capacitor on the +5V supply mitigate noise spikes.

A site dedicated for the AM Radio Amateur and vintage radio. Home of the AM Press/Exchange, The AM Forum (the largest BBS of it's kind),and The AM Classifieds, Photos, Audio, and technical information. Audio and Video chat rooms.

Best audio settings, modifications and tricks for the Yaesu FT-2000 by DK3HV

Sherwood Engineering Inc., based in Denver, Colorado, specializes in ham radio accessories and components. The company, located at 1268 South Ogden Street, offers a variety of products including filters, cooling kits, and audio switch boxes. Sherwood Engineering is known for its work with brands such as _Drake_, _Icom_, and Collins, providing components like 455 kHz mechanical and crystal filters. The company has also been involved in producing first-IF roofing filters and DSP protection filters. Sherwood Engineering has a history of over 45 years in the industry, though it has now retired from producing certain products like the SE-3 MK IV. Despite this, the company continues to provide technical resources and presentations on optimizing rig performance, with past events held at venues like the Dayton Contest University in 2014. The company operates Monday through Friday, from 9 a.m. to 5 p.m. Mountain Time, and accepts payments via PayPal, check, or money order. DXZone Focus: Denver | Filters | Icom

This tutorial provides step-by-step instructions for setting up the ICOM IC-7300 to work with WinLink and WinMor. The process begins with downloading the necessary USB driver from ICOM Japan, followed by configuring the radio settings through the menu. Key settings include selecting the correct output and data modes, as well as ensuring the USB serial function is properly set. Once the radio is connected to the PC via USB, the drivers will install automatically, allowing for seamless communication. After confirming the installation of the USB Audio CODEC and COM port, users are guided to download the RMS Client Software for WinLink. The tutorial emphasizes the importance of understanding the WinLink system and provides links to additional resources for setup. Finally, it details how to configure the WinMor modem settings, ensuring the ICOM IC-7300 is ready for effective digital communication. This guide is essential for operators looking to enhance their digital capabilities using the IC-7300.

Understanding Common Mode and Differential Mode Currents on Transmission Lines by K9YC

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