HF 10 watt amplifier for 18MHz using a 2SC1969/2SC1944 transistor - Ham RadioAF AmplifiersThis project and your efforts will provide you with a 0.55 3 watt input to easily 10 watt output. The two linear amplifiers are ment for use with QRP SSB/CW/FM/AM transmitters on the amateur bands 15 and 17 meters can be powered from a 12 volt DC supply. The design is a good balance between output power, physical size __ Designed by Guy Roels ON6MU
HF 5-band MOSFET power amplifier delivering 25 watts using a IRF510 - Ham RadioAF AmplifiersThis project uses a widely available IRF510 MOSFET. This N-Channel enhancement mode silicon gate power field effect transistor is an advanced power MOSFET designed, tested, and guaranteed to withstand a specified level of energy in the breakdown avalanche mode of operation __ Designed by Guy Roels ON6MU
HF TRANSCEIVER - This page will describe the construction of a multi band SSB transceiver. Because I do 99% of my operating on my four favourite bands, I decided to build a four band rig with provision for adding a fifth band later. The design can be used on any band from 160M to 10M. Mine covers 80M, 40M, 17M, 10M. __ Designed by EI9GQ homebrew radio
HF/6M Antenna Tuner Preselector & Antenna Switcher - Ham RadioBALUN, TUNERSSchematic __ Designed by Guy Roels ON6MU
HF/VHF mini portable tuner - If you elect to use an antenna tuner, it is extremely important that you understand exactly how to use tuners and what they can and cannot do. A few watts of RF can easily become lost in an incorrectly adjusted antenna matching device. The whole idea of a QRP station is to keep things simple and economical, so I cannot overemphasize the priority of a clean, efficient connection of the amplifier output to a resonant antenna. __ Designed by Guy Roels ON6MU
HF/VHF portable antenna tuner - Ham RadioBALUN, TUNERSSchematic __ Designed by Guy Roels ON6MU
High quality AM through your FM stereo - amateur radio construction projects. __ Designed by Peter Parker VK3YE
HomebreW 1 Watt 2.4 GHz Power Amplifier - Increase the RF output power of your wireless network card to 1 Watt. __ Amateur Radio circuits from Green Bay Professional Packet Radio
HomebreW 144 MHz to 2.4 GHz Transverter - Scan and monitor the 2.4 GHz band using a common MMDS downconverter. __ Amateur Radio circuits from Green Bay Professional Packet Radio
HomebreW 20m CW Transceiver - hand-drawn schematic __ Designed by MINOWA, Makoto 7N3WVM
HomebreW 30m CW Transceiver - hand-drawn schematic __ Designed by MINOWA, Makoto 7N3WVM
HomebreW 40m CW Transceiver - hand-drawn schematic __ Designed by MINOWA, Makoto 7N3WVM
HomebreW 6m DSB Transceiver - hand-drawn schematic __ Designed by MINOWA, Makoto 7N3WVM
HomebreW 6m SSB/CW Transceiver - hand-drawn schematic __ Designed by MINOWA, Makoto 7N3WVM
HomebreW Bi-Directional 2.4 GHz Amplifier Designs - Make your own amplifier for your 2.4 GHz wireless network. __ Amateur Radio circuits from Green Bay Professional Packet Radio
HomebreW Bi-Directional 915 MHz Amplifier Designs - Make your own high-power amplifier for your 900 MHz wireless network. __ Amateur Radio circuits from Green Bay Professional Packet Radio
IC oscillator 130MHz using 74LS04 chip - Ham RadioV-U)HF AMPLIFIERSchematic __ Designed by Guy Roels ON6MU
ICOM CI-V interface with RS232 RTS to PTT - This page describes my home-built ICOM CI-V interface. In order to connect most all ICOM radios to a computer, an additional interface is required. The interface bridges the gap between the RS-232 electrical levels used by the computer serial port, andthe open collector shared bus used by the ICOM radios. The interface, therefore, is not much more than a level converter
Improved 3 Transistor Audio Amp (80 milliwatt) - This circuit is similar to the one above but uses positive feedback to get a little more amplitude to the speaker. I copied it from a small 5 transistor radio that uses a 25 ohm speaker. In the circuit above, the load resistor for the driver transistor is tied directly to the + supply. This has a disadvantage __ Designed by Bill Bowden
Improved FM Stereo Modulator - This circuitry is used for generating a high quality FM stereo multiplex signal that is suitable for driving mono FM transmitters. The Rev E2 FM stereo multiplex generator is the most recent design in a series of circuits that have appeared on this site. This version features improvements to the audio mixer stage, better gain adjustments in the audio filter stage and a rework of the multiplexer stage. When it is adjusted properly, the Rev E2 design produces an FM stereo signal with excellent fidelity. __ Designed by Forrest Cook
KB9MWR Projects Page - Ongoing local amateur radio projects. __ Amateur Radio circuits from Green Bay Professional Packet Radio
Kenwood TR-7950 manual & Schematics - Being used in a mountain-top repeater, our TM451 transceivers suffered severe frequency shifts as the temperature varied. They are exposed to temperatures as low as -15C in winter and as high as 45C in summer, and the original crystal oscillator is too sensitive to this variations. We measured the repeater to be as high as 2.5Khz up or down in frequency depending on ambient temperature, and we looked for a solution. |