20 meters CW QRP Transceiver - The little QRP presented in this article may be built in a gradual manner, in fact it is divided in two main modules (plus VFO) , you may also complete only a single part (RX or TX module). Also the VFO module may be built with two complexity levels, as a conversion VFO or as a free oscillator, obtaining slightly different performances. __ Designed by Francesco Morgantini IK3OIL 20m SSB Transceiver, with DDS, PIC16, 10.7Mhz IF - My Radio amateur callsign is OZ2CPU. I like to use Atmel AVR Atmega PIC 16 PIC 16F876 PIC 16F84. Most electronics easy made for the novice and something is for the more experienced. __ Designed by Thomas Scherrer OZ2CPU
2N2222 40 Meter CW/DSB Tranceiver - in spring of 1998, NorCal sponsored a contest to design and build a project using no ICs and 22 or fewer 2N2222s as the active semiconductor devices. I thought this was a really intriguing idea, so I set about to design my version __ Designed by Monty Northrup
3.3V converter Delivers 3W from Li-Ion battery - 11/05/98 EDN-Design ideas (Several circuits here, scroll to find this one) Lithium-ion batteries are rapidly gaining popularity in portable applications because of their superior energy density, low self-discharge rate, and high cell voltage. When you use one Li-ion battery to power a 3.3V DC/DC converter; however, you encounter a problem, because the battery voltage. Design by David Salerno, Unitrode Corp, Merrimack, NH
3.3V lithium-cell supply requires one inductor - 08/05/99 EDN Design Ideas: Because of growing popularity of lithium-ion (Li-ion) batteries and 3.3 V power supplies, portable-equipment designers must often create a 3.3 V supply that a single Li-ion cell can power Design by Matt Schindler and Jay Scolio, Maxim Integrated Products, Sunnyvale, CA
30 Meter, Discrete Component CW Transceiver Built Manhattan-style - The 2N2/30 claims its heritage from the 2N2/XX platform, but also uses non-2N2222 transistor types and commercial mixers. From the beginning, it was to be a test bed for building with surface mount parts in a Manhattan-style construction environment. __ Designed by Jim Kortge, K8IQY
40 meter SSB QRP transceiver - in 1987 I built this radio. it has been published in a national ham radio magazine, and now finally found its way into the web! __ Designed by Manfred Mornhinweg
40 meters CW QRP Transceiver - This project describes a little QRP transceiver “full legal power” (5 W at 12 V) for the 40 meters band. The RiG may be built in a gradual manner, in fact it is divided in two main modules, or you may also complete only the RX module __ Designed by Francesco Morgantini IK3OIL
40 to 6 Meter "No Tune" Transverter - This project is a 40 meter to 6 meter CW "no tune" transverter using ten 2N2222 transistors and one 2N2907. The transverter requires 2 watts of drive from a 40 meter cw transceiver and outputs 2 watts on 6 meters. On receive, it uses the 40 meter rig as the intermediate frequency amplifier. its receive sensitivity is approximately 0.5 microvolts. Transmit spurious outputs are less than -50 dBc, meeting FCC spectral purity at a 2 watt power level. All transmit/receive switching is solid state. __ Designed by Jim Kortge, K8IQY
418/433 MHz short-range communication (Elektor Electronics article) - The history of licence-exempt use of radio transmitters started a few decades ago with the private use of low-power transmitters for radio-controlled models. Much later, CB radio in the 27-MHz band was legalised and type-approved radios for this band were freely available. __ Designed by Peter Jakab
49MHz Walkie Talkie - Lots of people are requesting walkie-talkie and RF remote control schematics, so here is some. Building se circuits needs special equipment and expertise in RF circuits. if you are going to experiment with se circuits, please note that I did not build __ Designed by Peter Jakab, Electrical Engineer, Engineer of Informatics
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
5 Watt 80 Meter QRP CW Transceiver - A great deal of interest has been generated by my previous design articles, so I decided to go to work on a full blown transceiver design. After several months of work, the ROSE-80 transceiver was born. This transceiver is similar to other designs but contains some unique differences. This design boasts the following features __ Designed by Radio Amateur Society of Norwich
6m SSB & CW QRP transceiver - The concept of the 6m SSB & CW transceiver is similar to the 80m SSB & CW transceiver, described on this web site with some minor changes in AGC and audio PA. An additional RF preamplifier, which is not needed on 80m, has been added to get enough receiving sensitivity. The VFO is built as VCXO with frequency doubler, now. __ Designed by Aleksander Stare
6M Transverter - 17M to 6M transveter. __ Designed by EI9GQ homebrew radio
72 part contest rig - This 30 meter rig with superhet receiver and xtal controlled transmitter won "Honorable mention" in the 2010 FDiM ACRI design contest. Uses a LM386 audio amp as a combination product detector / audio amp. __ Designed by Steven "Melt Solder" Weber KD1JV
75 Meter SSB Transceiver - Here's 75 Meter QRP SSB Transceiver. in general, the transceiver switches the 4-element 1500 ohm xtal BPF ends between the inputs and outputs of the two SA602s to reverse the signal flow for R/T operation. Since no iF amplifier is used in the design, 20 dB of additional receiver gain is produced by the 2N2222 receiver RF amplifier, while automatic gain control (AGC) is produced by the peak DC swing of the LM386 output passed through a rectifier and filtered by a capacitor and fed to the gate of a BS170 enhancement mode FET acting as a variable resistor across the input of the LM386. Both receive and transmit band pass filtering are done by the same half-pI BPF. The diode pair in the mic circuit reduce the "chirp" that occurs during the R/T transition. Additional BS170s could easily be used to mute both the mic and audio instead of the R/T switch directly. These BS170s would be controlled by the +R and +T voltages on their gates while their drains would be tied to 1) the mic circuit between the two coupling capacitors and 2) pin number 1 (audio in) of the LM386 (BS170 sources to ground). Additional power output (perhaps 60 mW) could also be attained by connecting the RF output transistor's collector choke (10 uH) to a 9 V supply instead of the 5 V. Additional biasing current might also be required for this change.__
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 Meter, 5 Watt CW Transceiver - A great deal of interest has been generated by my previous design articles, so I decided to go to work on a full blown transceiver design. After several months of work, the ROSE-80 transceiver was born. This transceiver is similar to other designs but contains some unique differences. This design boasts the following features __ Designed by Radio Amateur Society of Norwich
A 40 meter QRP-Transceiver - This was one of my very first transceiver developments. This page was also one of the very first circuit descriptions that I put on the internet quite some years agon. Today I would not build a transceiver like I did then, but it was working, so__
A homemade replacement for the Yaesu FTS-8 subtone encoder - Using just a PIC and an active filter! __ Designed by Manfred Mornhinweg
AC Power Line Remote Alert - Beeper and/or LED remotely-operated via mains supply line; Simple circuitry, easy to build units __ Contact Flavio Dellepiane, fladello @ tin.it
AGC Circuit - SSB SSB Transceiver-Receiver Section: The AGC circuit uses a dual op-amp IC . The first stage amplifies the receive audio (taken from the hot side of the AF gain control). The output from this stage is converted to a DC (ish) signal by a voltage doubling rectifier. The final stage is a DC amplifier. A nice feature of the circuit, is that the meter is automatically set at zero, in the absence of any signal. I used an LF353 dual op-amp. Most fet input dual op-amps should work in this circuit, or you can use a pair of single op-amps. __ Designed by EI9GQ homebrew radio
ALT-Altoids L Tuner - Altoids L Tuner (ALT) "L" tuner for half wave end feed antennas. __ Designed by Steven "Melt Solder" Weber KD1JV
An automatically tuned HF Mobile antenna - This elegant design covers the complete spectrum from 7 to 30 MHz at less than 1.3:1 SWR, is compact, very weatherproof, robust and has good performance. This article was first published in the QEX / Communication Quarterly magazine. The article comes in five pages, with lots of photos, mechanical drawings, schematic diagram, PCB layout and software listing. Exact duplication is not for the faint of heart, but some of you may find individual parts and ideas useful for your own projects! __ Designed by Manfred Mornhinweg
Audio Amplifier - SSB Transceiver-Receiver Section: The AF amp has about 60 to 70 dB of gain. The transistor is a BC109C. I might try replacing it with a lower gain device. A typical 59+ signal, gives more than a volt pp at the collector. The power amplifier IC is an LM380N (14 pin version). if you intend to use the rig on CW, the LM380N must be powered up on transmit as well as receive (for the sidetone osc.). __ Designed by EI9GQ homebrew radio
Balanced Modulator - The simple, two diode balanced modulator is still one of the best ways of generating a DSB/SSB signal. You can use Silicon switching diodes, 1N914, 1N4148, Germanium point contact diodes, 1N34, or Schottky (Hot Carrier) diodes. I used a pair of 1N34's. You should spend a few minutes with a fistful of diodes and a multi-meter to find a pair that are well matched for forward and reverse resistance. Both transistors are BC548's, for the reasons mentioned above. __ Designed by EI9GQ homebrew radio
BPF and Mixer - SSB Transceiver-Receiver Section: The signal from the RX/TX relay is filtered by an 80Mtr band pass filter. This can be replaced by a filter for another band or a bank of switched filters, for a multI band rig. if you need to cover from 3.5 to 4.0 MHz, you will need to replace the 10p coupling capacitor with one of a larger value (about 18p). You can wind your own inductors, about 18 turns on a 10K type Toko former will have 5.5 microhenries of inductance. __ Designed by EI9GQ homebrew radio
Build a PC Infrared Transceiver - Add infrared capability to your PC for peanuts.__ SiliconChip
Convert 2m VHF FM PMR Transceiver Motorola Radius M110 into an AM ateur Radio - Turn a professional 2m VHF FM PMR transceiver Motorola Radius M110 into an amateur radio __ Designed by Aleksander Stare
Exciter for SSB Tranceiver - Now that people are getting married, and having babies on the internet, isn't it about time someone designed and built an SSB rig on the net?. The rig will be built up from various modules, starting with the SSB exciter board. The first prototype board has been built and tested on the bench but not on air. The resulting SSB signal looks good on the scope, and sounds ok on a monitor receiver. __ Designed by EI9GQ homebrew radio
Extending the Applications of 5V Powered RS-232 Transceivers - DN14 Design Notes__ Linear Technology/Analog Devices
Family Radio Service (FRS) to 900 MHz Transverter - Schematic only, not description included__ Green Bay Professional Packet Radio
FodTrack - My world-famous realtime satellite tracking system! __ Designed by Manfred Mornhinweg |