5 watt mini-amplifier 28Mc (or 27Mc CB) with one transistor - Ham RadioV-U)HF AMPLIFIERSchematic __ Designed by Guy Roels ON6MU
50MHz converter project based on a NE602/SA602/NE612 - This is a very sensitive 50Mc converter allowing you to receive the entire "Magic Band" (50Mc 52Mc) on your general coverage receiver (28Mc 30Mc). It receives all types of modulated transmissions. It all depends on the receiver used. I've tested this project on a allmode Yaesu FRG-100 receiver. Within certain limits you can change the output frequency to suit your needs. The converter is very stable, low nois, sensitive and low on power consumption and can be compared to many commercial 50Mc receivers. __ Designed by Guy Roels ON6MU
60 Watt RF Amplifier - Soild state RF power amplifier using IRF840. Simple and easy to construct. IRF840 can handle a maximum power output of 125 Watts.
600 Volt Power Supply - Simple 600 Volt DC power supply. Convert 230V AC to 300V and 600V DC.
60W Linear Amplifier - The 60 Watt linear amplifier is simple all solid state circuit using power MOSFET IRF840. The IRF series of power transistors are available in various voltage and power ratings. A single IRF840 can handle maximum power output of 125 watts. Since these transistors are used in inverters and smps they are easily available for around Rs: 20/- __ Designed by Mohamed Agha
60W MOSFET Amplifier - To celebrate the hundredth design posted to this website, and to fulfil the requests of many correspondents wanting an amplifier more powerful than the 25W MOSFET, a 60, 90W High Quality power amplifier design is presented here. Circuit topology __ Contact: Flavio Dellepiane, fladello @ tin.it
74 MHz Hallogene Lamp Radio-Controlled - This circuit is a 73 MHz Hallogene Lamp Radio-Controlled. The purpose of it is to control the power state of a hallogene lamp by a remote control. When we press the push botton of the remonte control, the power state of the lamp will be changed, so, if the lamp was turned on, it will turned off and if it was turned on, it will turned off. If we press to the button another time, the same action will be occured. When the button is pressed, a LED indicator lights on the remote control __ Designed by Serge Saati
7MHz SSB Transceiver - Circuit diagram and brief description of 7MHz SSB Transceiver for Hams. The circuit is designed around two numbers of MC1496. It can push around 80 Watts with IRF840 in final. You can down load HTML version or printer friendly word document. __ Designed by Yujin Boby
80 METRE RECEIVER - This 80M receiver design includes the necessary switching to allow the SSB filter and first I.F. amplifier to be used for transmitting. The receiver stages from R.F. input to speaker output will be described in detail below. __ Designed by EI9GQ homebrew radio
807 & 1625 Valves - data on vacuum tubes 807 and 1625 used in ham radio transmitters. Describes various pin voltages and different operation modes.
80m band direct conversion receiver - The first differential amplifier inside the NE592 is used in this application (unlike it's normal function) as a symmetrical mixer. For mixing purposes the oscillator signal is fed to both emitter terminals (pin 2 and 7) in parallel. Received signals from the CW segment preferably reach the NE592 differential input due to a pre-selection of a 3560 kHz tuned input filter. __ Designed by DL2YEO
80m SSB & CW QRP superhet transceiver - The 80m SSB & CW transceiver an already proven concept used in ATLAS amateur transistorised transceivers from 70's. The "two-mixer + 1 XTAL filter" design uses the 1st mixer as front-end mixer on receive as well as SSB modulator on transmit. The second mixer is used as SSB product detector on receive and as a heterodyne mixer on transmit. VFO and BFO are cross-switched between both mixers with a PIN diode matrix. Between 1st mixer's output and 2nd mixer's input a crystal filter is placed, followed by an AGC PIN attenuator __ Designed by Aleksander Stare
80W RF Amplifier 88-108 MHz - This is 80W RF power amplifier that boosts FM Transmitter's power using 2SC2782 bipolar transistors in a tuned class C circuit. RF amplifier can be driven to full 80W power with less than 1 watt driving input power, so that a large gain margin results in this FM transmitter. To obtain stability in this RF amplifier, I employed several techniques, such as placing the resonances of base and collector chokes far apart, damping the chokes with resistors, using RC combinations for absorption of unwanted frequencies, using feed trough capacitors for bypassing on the board, etc. It took some tweaking, but the amplifier ended up unconditionally stable.
8W Broadband FM RF Amplifier - Here's 8W broadband FM RF amplifier using 2SC1971 VHF power transistor. The RF Amplifier PCB layout designed for FM broadband 88-108 MHz transmitters using microstripline technique. This 8W RF amplifier circuit provides an appropriate power boost for transmitters with an input of 500 mW.
90 MHz voltage controlled oscillator for FM Band - Notice the abundance of 2N4401, 1 k resistors and 330 Ohm resistors? That's because I have a lot of each.2N4401's weren't intended to be used as varactors, but they work just fine. Don't be afraid to experiment with the parts you have on hand. Build this on a ground plane board. Layout is important. __ Designed by Dick Cappels