DIY Antennas, QRP, SDR & Ham Radio Projects from VU3DXR
Audio processors and Speech compressors are important in SSB radio because they can help improve the transmitted signal’s quality. Here are complete resources and links available in the internet connected to Mike Preamplifier/Speech compressors/Speech Processors Dyna Audio compressor Noise Canceling Electret Microphones – WB9YBM Microphone Speech Processor Microphone Amplifier with ALC Audio compression with transistors […]
This article presents a simple, low-cost audio compressor circuit designed to stabilize microphone signal levels. It reduces dynamic range by softening loud sounds and boosting weak ones, improving clarity and intelligibility. Built with basic components, it suits amateur radio and DIY audio setups, offering consistent output without complex or expensive hardware.
A short linear loaded ham radio band HF antenna is a type of antenna that uses linear loading to reduce its physical length. Linear loading is a technique that involves adding parallel conductors to the antenna elements. This increases the antenna’s effective length, allowing it to operate at a shorter physical length. Short linear loaded […]
This 80M Trapped dipole antenna is the work of Nadisha 4S7NR, modified by YC0HLE which results are matched at a frequency of 3,845 MHz. This design will be resonant at a frequency of around 3,250MHz to 3,850MHz. Coil inductance = 67.83 µH, made of email wire diameter = 1 mm, diameter of the cocker = […]
SSM2167 audio processor for Baofeng Mic enclosure Mic gain is barely adequate on the µBITx transceiver since there is no Mic Gain control. It would also be helpful to not only provide mic gain control, but to add compression in order to boost the average power output.The SSM2167 is a powerful audio processor that can […]
This article describes a simple microphone compressor built with three transistors to improve audio consistency. The circuit uses a preamplifier, buffer, and feedback stage to control gain. As input increases, negative feedback reduces amplification, compressing louder signals. It runs on 12V and suits amateur radio setups needing stable, balanced voice output.
This project uses an SSM2167 IC as a complete microphone preamplifier with built-in compression and noise gating to improve uBITX transceiver audio. It boosts mic gain, reduces dynamic range, and suppresses background noise, resulting in clearer, louder, and more consistent transmitted speech.
Modified simple horizontal V antenna This antenna is little modified version of antenna designed by Adam 9A4QV for noaa/METEOR Weather sat reception. Adams antenna is based on a very simple linearly polarized dipole, which makes construction almost trivial. I tried his antenna and found that practical difficulties in finding choc block terminals. Chock block terminals are not strong enough […]
This article explains how to build a low-cost ribless programming cable for Motorola GM360, GM338, and GM300 radios. It uses a USB-to-TTL adapter, RJ45 connector, and a diode to enable direct serial communication without a RIB unit. The guide covers wiring, setup, and software configuration for reliable radio programming.
Decoding the Motorola GM300 model number provides critical details about the radio’s specifications, such as frequency band, power output, channel capacity, and more. The GM300 model number typically follows Motorola’s standard convention, with the first six characters indicating the base model and the subsequent characters specifying features like RF power, frequency range, channel spacing, and […]