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Kenwood TH-D7a TX band modification

Modifications for the Kenwood TS-870S

The practice of converting computer server power supplies to make a very high quality high power supply at low cost is attractive. It doesn't normally require any modification to the supply but the hard part is figuring out how to trick them into turning on.

Diamond W8010 Multiband Dipole Modifications

Throughput improvement for the FT726R - Tapr PSK modem

A 200 kHz bandwidth digital transmission system for image transfer in the Amateur Service is under development, specifically targeting VHF allocations. John B. Stephensen, KD6OZH, leads this project under an FCC Special Temporary Authority (STA) valid until September 10, 2006, authorizing emissions up to 200 kHz bandwidth in the 50.3-50.8 MHz segment. Current regulations typically limit bandwidths to 20 kHz on VHF amateur bands, making this STA crucial for testing wideband digital modes. The modem, a modified **OFDM** (Orthogonal Frequency Division Multiplexed) unit, was initially tested on the 70-cm band. It splits a high-rate data stream into multiple low-rate subcarriers to mitigate multipath echoes. The system uses a DCP-1 card with a Xilinx XC3S400 FPGA and Oki Semiconductor ML67Q5003 microcontroller. The transmitter, located at 36d 46m 30s N, 119d 46m 22s W, generates 150 WPEP into an 8 dBi gain vertical antenna, while the mobile receiver uses a Ham-stick. Three data formats for 50, 100, and 200 kHz channels are being tested, with encoded data rates of 96, 192, and 384 kbps. Verilog code for the VHF OFDM modem is 95% simulated, with modifications from the UHF version including increased filter coefficient precision and a change from Ungerboeck **TCM** to BICM for improved performance over fading paths. Final tests will involve one-way over-the-air measurements of bit error rates and coverage area.

Extending frequency to FT-290R for transverter use

YAESU FT-1000MP Mark V ESSB Modifications pdf file

Modifications to the Tigertronics Signalink USB sound card

A custom modification RC-D710 GPS-INSIDE mod.

How to enable a full TX coverage on the Yaesu FTDX101D the european version.

9600 Baud modification on the Kenwood TM441 by ON6MU

Constructing a high-power 70cm solid-state amplifier presents unique challenges, particularly when aiming for 500 watts output using modern LDMOS devices. This resource details the author's experience building a 70cm amplifier based on a _Freescale MRFE6VP5600H_ transistor, initially from an RFHAM kit. It meticulously outlines the necessary modifications to achieve advertised performance, including optimizing input and output matching, correcting bias circuitry, and ensuring proper output balun connections for stability. The author shares specific adjustments, such as trimming the prototyping board for better transistor fit, drilling additional mounting holes for improved heat sinking, and replacing original matching capacitors with a single _20pf MIN02 metal mica_ for superior output. A critical fix involved jumpering gate decoupling pads to balance the push-pull transistor halves, which increased output to 580W and improved IMD. The resource also highlights a crucial correction to the output balun connection, initially reversed in the _Dubus_ article schematic, which resolved intermittent stability issues. Test results are provided, showing input power, output power, and drain current at 50V, demonstrating the amplifier's performance after modifications. This practical account offers valuable insights for hams undertaking similar high-power UHF amplifier projects, especially those working with LDMOS devices and kit-based constructions.

Collection of Kenwood TL-922 linear amplifier modifications

A collection of modifications and improvements to the Ameritron ALS-600 ham radio RF power amplifier

Kenwood TS 990S, Military Auxiliary Radio System modification

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.

This kind of antenna has grown in popularity over the last years because it gives you a decent performance and triband capabilities. But its 50 MHz design is far from optimal. Here you can learn how to improve its 50 MHz performance in a very easy way.

North West CB Radio is a page with radio modifications’s, Local Portland’s Traffic info, Trucker things like CB slang, DX info and a forum. Also we host The Saturday Night Stomp Fest in the Portland area. Results are posted weekly.

An illustrated modification for the Icom IC-R20 receiver to locate and use the unfiltered audio.

Kenwood TS-2000 Transmit / Receiver eSSB Modifications by N3GX

CW and SSB INRAD narrow filters modification

Adding 17 meter band to Mosley TA-33M yagi antenna

A modification to improve quality of built-in FT-817 Noise Blanker

General modifications applicable to any Elecraft K2

Modification leaves nearly all of the existing Omni agc circuitry intact, simply add an audio detector which modifies the delay characteristics of the original system by G3IXQ

Modification to solve key clicks on FT 1000 MP

Demonstrates a specialized DX cluster monitoring application, _DxWatcher_, designed for Windows environments. It processes DX spots received via Telnet/Internet, presenting them in a filtered table and a dynamic bandmap. The software integrates with transceivers, specifically the FT-2000, to read VFO frequency and enable one-click tuning to spotted stations. _DxWatcher_ version 1.0.3.0, released on 13 June 2020, includes minor bugfixes and improvements such as enhanced recovery from suspend mode. Key features include configurable bandmap position and size, automatic opening, and bolding of spots received within the last **10 minutes**. The application utilizes the standard _ctry.dat_ file for DXCC country analysis, allowing users to update it for current DXCC status. Source code, developed in C# with MS Visual Studio 2008, is freely available, encouraging modification and sharing while requesting retention of the original author's callsign.

Some modifications for the Tigertronics Signalink USB sound card radio interface

The _Nomenclature Française_ offers an online callbook service specifically for French amateur radio operators and SWLs. This resource facilitates searching for stations by various criteria, including callsign, operator name, city, and postal code. Search results typically display the operator's identity, full address, email contact, and personal website link, if available and publicly listed. The platform serves as a central database for the French amateur radio community, maintained by the _REF Union_. It provides a direct mechanism for operators to request modifications or new insertions of their data into the online nomenclature, ensuring current and accurate listings. The service is a fundamental tool for QSLing, locating fellow hams, and verifying contact information within France. Authored by _F6BIG_, the callbook is a key utility for French hams.

A forum post at WZ5Q with modifications of Kenwood TS-2000 audio fratures

Keyclicks and NB modifications for the Yaesu FT-1000MP Mark-V HF transceiver

A different implementation of the G7FEK HF multiband antenna with some adjustments and modifications

Freeband modification for the Yaesu FT-100

Modification and verification of the FT847 to optimize 70 MHz performance by G4FUF

Tower erection service, modifications, replacement, repairing service

The intent of this article is to help the semi-non-technical person understand what is inside the Drake TR-7(A) Transceiver, how it works, and discusses simple adjustment and modifications the end-user can perform

A collection of modifications for the Icom IC706 transceiver

Collection of modifications for the Heath HW-7

The antenna in this project is a modification of the techniques used to design a multiband fan type dipole with little or no tuning involved having a total space of 105 feet

Describes Atlantic Tower Services (ATS), a company specializing in antenna tower erection and maintenance, operating from Orlando, Florida. ATS offers a range of services including site maintenance, structural repairs, system modifications, and complete tower installations for various communication needs. The company emphasizes its capability to handle diverse tower projects, from routine inspections to complex upgrades, ensuring structural integrity and optimal performance for amateur radio and commercial installations. ATS focuses on delivering reliable infrastructure solutions, supporting the backbone of communication systems. Their service portfolio covers critical aspects of tower ownership, addressing both preventative care and reactive solutions for existing structures. They are equipped to manage projects involving different tower types and heights, adhering to safety standards and operational best practices. Services include **site maintenance** and _structural modifications_.

Solving interference from television channel 11 on 144MHz transverters by Chris Cox, NØUK, G4JEC

A kit Digital VFO with pre-soldered surface mount parts and burned-in firmware, a scratch build with Arduino Nano, C code with modifications, and a Silicon Labs si5351 PLL clock generator on a breakout board.

Adding a 20m band pass filter for the Icom IC-706MkII(G) by ON7EQ

Softrock Version 6.1 Software Defined Radio experience and modifications by DF9CY

Mods.dk modifications for the Kenwood TS-690

With this mods you get more power, about 60W output on 4m from the Yaesu FT-847, mod by G4FUF

Drake Mods for R4B and R4C models by VE3EFJ

A simple Drake R-4C receiver power supply modification

Mods for Kenwood TS-950SD / SDX