There are 181 circuit schematics available in this category. Click here for all circuit diagrams. Last circuit added on Thursday, 30 July 2015.

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CircuitCategoryDate AddedOK?Votes 
4 channel 433MHz remote control transmitter / receiver based on SM5162 and SM5172 chipsRF 3
SCA Adapter - listen to advertisement free background music on FM broadcast radioRFSep 23, 20090
Experimental DSB/CW QRP rig for 20 and 40 meter bands (PDF)RFOct 05, 20091
Simple 40 meters CW QRP Transceiver (PDF)RFOct 05, 20091
20 meters CW QRP Transceiver (PDF)RFOct 05, 20090
USB 0-500MHz RF Power Meter based on a AD8307RFFeb 21, 20130
Simple FM receiver based on a TEA5591 ICRFMar 23, 2015-1
Electronic Eavesdropping Devices DetectorRFJun 26, 20091
Radio Wave AlarmRFJun 26, 20090
Linear FM 50Watt with BLY90RFJun 28, 20090
Send Morse on your VHF RigRF 1
An end-fed antenna, L-match coupler and resistive bridge for HFRF -1
Regenerative receiver for the AM broadcast band using two transistorsRF 0
Novel crystal set requires no antenna, earthRF 0
80 meter direct conversion receiverRF 0
A compact L-match ATU for portable useRF 0
Converter to yune six metres on your two metre receiverRF 0
High quality AM through your FM stereoRF 0
Converter to Hear Amateurs on your FM RadioRF 0
RF Actuated Keying MonitorRF 0
LF to HF ConverterRF 0
Super 80 ultra-simple SSB receiver for 3.5 MHz a basic superhetRF 0
Basic 10GHz / 24GHz gunplexer / gunn diode control circuit (PDF)RF 0
50 MHz to 10 MHz receive converterRFJun 19, 20110
17M to 6M transveter circuit diagramRFJun 19, 20110
metre receiverRFJun 19, 20110
T-Match ATU (antenna tuning unit)RFJun 19, 20110
Single transistor receiver for SSB, CW, AM using a VHF dual gate MOSFETRFJun 19, 20110
Multi band SSB transceiver construction projectRFJun 19, 20110
Receiver building blocksRFSep 06, 20010
Digital display and VFO stabiliser using a PIC microcontroller and LCDRFJun 19, 20111
SSB transceiver for 80MRFJun 19, 20110
VHF receiver convertererRF 0
Circuit diagrams for 418/433 MHz short-range communication (Elektor Electronics article)RFApr 12, 20140
Circuit diagram for superregenerative receiver built by GE labsRFApr 12, 2014-1
X10 RF daughter board - receiver circuit diagramRFApr 12, 20140
RX3302 433MHz superregenerative receiver module circuit diagramRFApr 12, 20140
Automicro RX3304 receiver module schematicRFApr 12, 20140
49MHz walkie-talkie circuit diagram that uses only three transistorsRFApr 12, 20141
Superregenerative 27MHz receiverRFMar 23, 2003-1
Montreal Doppler 3 DF (direction finder) unitRFApr 14, 20110
Construction details for 30 meter rig with superhet receiver and crystal controlled transmitterRFApr 12, 20140
All Discrete Components 40 M transceiver with super-het receiver using no IC'sRFApr 12, 20140
Versatile L tuner for end feed wire antennas that fits in an Altoids tin.RFApr 12, 20140
MMR-40 40 meter rig with SSB (voice) and CW (Morse code) operating modes.RFApr 12, 20140
An 80 meter rig for the MAS contest by KD1JVRFApr 12, 20140
A unique PSK transceiver, Version 2 By Steven Weber, KD1JVRFApr 12, 2014-1
(Fairly) Simple 75M SSB rig with PTTRFApr 12, 20140
AM Short Wave Broadcast Receiver circuit diagramRF 0
Universal USB digimode interface supports CAT (Yaesu), CI/V (Icom) and RS-232 (Kenwood) units (PDF)RFOct 07, 20090
Convert 2m VHF FM PMR transceiver Motorola Radius M110 into an amateur radioRFJun 18, 20030
Simple CW identifier for a FM repeater (PDF)RFOct 07, 2009-1
6m SSB & CW QRP transceiverRFOct 07, 20090
80m SSB & CW QRP superhet transceiverRFOct 07, 20090
Pocket sized 20m (30m) CW QRP transceiverRFOct 07, 20090
USB / CAT (CI-V) adapter tested with FT-8900, FTB-9800, VX-7R, VX-7, FT-817 and IC-706MkIIGRFOct 07, 20090
Wideband SWR meterRF 0
SCA Subcarrier Demodulator for FM broadcast stationsRF 0
118MHz to 136MHz aircraft receiver circuit diagramRFJul 03, 20110
Shortwave received circuit diagramRFJul 03, 20110
Beat frequency oscillator for AM/SW radio receiversRFMay 25, 20120
Direct conversion 7MHz receiver using NE602RFMay 25, 20120
WWV receiverRFMay 25, 2012-1
1.5 GHz PLL Frequency SynthesizerRFApr 10, 20140
Transverter for Converting SSB CB to LF for Thru-the-Earth Voice CommunicationsRFMar 03, 20110
Simple ADS-B aircraft transponder decoder based on a PIC18F2550 microcontrollerRFDec 09, 20100
Active RF antennuatorRFApr 14, 20110
Simple Time-Difference-Of-Arrival RDFRFApr 14, 20110
555 Time-Difference-Of-Arrival RDFRFApr 14, 20110
50MHz converter project based on a NE602/SA602/NE612RF 0
HF/6M Antenna Tuner Preselector and Antenna SwitcherRF 0
MW Enhanced Crystal Receiver using 741 ICRF 0
455 Khz MF to AF converter used for DRM reception in a Yaesu FRG-100 receiverRF 0
Sensitive LW/MW/SW Shortwave general coverage receiverRF 0
MW/SW Radio receiverRF -1
Bipolar transistor RF mixerRF 0
HF/VHF mini portable antenna tunerRF 0
RF Power meter / dummy loadRF 0
SWR bridge covering HF to VHFRF 0
HF/VHF portable antenna tunerRF 0
Aircraft Radio Communications ReceiverRFSep 01, 20090
Crystal RadioRFSep 01, 20090
Class B series modulatorRF -1
Build a Crystal Set (simple AM radio receiver)RFApr 10, 20140
Precision Frequency Control for AM Radios - A Frequency Synthesized Local OscillatorRFApr 10, 20140
DSP-RDF Doppler Radio Direction Finder circuit schematic - complete kit availableRFApr 14, 20110
50O Load and Power MeterRFFeb 21, 20130
External antenna for the GPS-38, Magellan 2000, or Eagle Explorer GPS receiversRFMay 01, 20040
175KHz inductive pulse receiver (PDF)RFJan 26, 20010
200-400 MHz voltage controlled oscillator (PDF)RFJan 26, 2001-1
AM/FM/SW active antennaRFJan 26, 20010
RF Sniffer under 0.5MHz to above 500MHzRFJan 26, 20010
Electronic Eavesdropping Devices Detector (bug detector)RFFeb 21, 20050
CB (27MHz citizens band) receiverRFFeb 21, 20050
AM BCB radio receiverRFOct 23, 20020
Regenerative shortwave receiverRFJun 08, 20020
RF front-end for triple conversion GPS receiver (PDF)RFMar 01, 20030
7MHz SSB TransceiverRFMay 01, 20040
AM receiver circuit diagramRFSep 08, 20090
inexpensive high speed microwave data link using an Alpha Gunnplexer for 10 Mbps data rateRF 0
15M CW Transceiver designRF 0
20 Meter CW TransceiverRF 0
30 Meter, Discrete Component CW Transceiver Built Manhattan-styleRF 0
K8IQY's Original 2N2/40 CW Transceiver RigRF 0
40 to 6 Meter "No Tune" TransverterRF 0
SW30+ 30 Meter CW TransceiverRF 0
Wave Bubble self-tuning portable RF jammerRF 0
Wave Bubble - A design for a self-tuning portable RF jammerRFOct 12, 20090
Simple home made ADS-B receiver that takes IF from a modified receiverRFOct 04, 20100
Very Simple ADSB Receiver using a TV tunder to allow reception of aircraft transpondersRFOct 04, 20100
115200 RS232 QPSK RF modem projectRFOct 04, 20100
Yaesu FT-736R doppler compensationRFAug 14, 20020
30M PSK31 Transceiver circuit diagramRFFeb 25, 20030
SOP receiver (PDF)RFOct 30, 20020
SOP direct conversion receiverRFJan 06, 20020
Electroluminescent Receiver Kit includes circuit diagramRF 0
Receiver based on NE602RFJan 26, 20010
DC40 - 40M Direct Conversion receiverRFOct 08, 20090
Simple Dual Band SSB Transceiver (20/40 meters)RFOct 08, 20090
40m band direct conversion receiverRFJan 06, 20020
80m band direct conversion receiverRFJan 06, 20020
Regenerative Short Wave RadioRF 0
Homebrew 20m CW TransceiverRF 0
Homebrew 30m CW TransceiverRF 0
Homebrew 40m CW TransceiverRF 0
Homebrew 6m SSB/CW TransceiverRF 0
Homebrew 6m DSB TransceiverRF 0
FPGA Based ADS-B Receiver and DecoderRFDec 09, 20100
136 kHz direct conversion receiverRFJan 06, 20020
Audible S-MeterRF 0
40 Segment LED S-Meter circuit diagramRF 0
20 Watt GaAaFET Power on 2.3 GHzRFJun 13, 20020
High Frequency VCO Design and SchematicsRFOct 25, 20140
Dopler RDF (radio direction finder) circuitRF 0
VFO from 2001 ARRL Handbook, page 17.74RFNov 01, 20020
VFO from 2001 ARRL Handbook, page 14.20RFNov 01, 20020
Assorted RF circuitsRFMar 18, 20030
14MHz SSB 10mW TransceiverRFFeb 24, 20030
VLF radio receiver schematicRFApr 17, 20041
VLF Upconverter for Shortwave ReceiverRFSep 13, 20060
Basic Vox CircuitRF 0
Variable Bandwidth CW FilterRF 0
An Inexpensive Tone EncoderRF 0
5 watt, 80 meter QRP CW TransceiverRFJun 08, 20020
Two Transistor Reflex RadioRFAug 17, 20090
R2T2 Haywire Home StationRFOct 07, 20090
ICOM CI-V interface with RS232 RTS to PTTRFMay 01, 20040
Active Antenna AA-7 HF/VHF/UHF, 3-3000MHzRF 0
Active antenna 1 to 20dB, 1-30 MHz rangeRF 0
Active Antenna for AM-FM-SWRF 0
FM radio active antennaRF 0
Aviation band receiverRF 0
Bug detector with beep using 7413 or 74LS13RFJan 26, 20010
Bug detector / countersurveillance monitorRF 0
Basic RF oscillatorRFJan 26, 20010
Subcarrier adapter to listen to hidden subcarrier signals on FM radioRF 0
Morse Code Beacon KeyerRFSep 21, 20060
Improved FM Stereo ModulatorRFJul 09, 20020
The House Finch Direct Conversion Tube ReceiverRFMay 19, 20150
WB0RIO Piglet 6U8A Regenerative Receiver (Tube based)RFMay 19, 20150
QRP Antenna TunerRFSep 21, 20060
Smooth Tone Clickless CW Sidetone GeneratorRFSep 21, 20060
High Fidelity FM Stereo Modulator (Rev E2)RFMay 19, 20150
Variety of receiver converter projectsRFApr 24, 20010
One transistor FM receiverRFApr 24, 20010
42 Mc Band to 88 Mc Band (retrofit converter) ProjectRFApr 24, 20010
RF noise bridge for HFRF 0
160m mini portable End Fed Half Wave Tuner - MkIIRF 0
Crystal radio circuits including diode performance comparisonRFMar 10, 20030
VK5JST Aerial analyserRFJun 24, 20150
A dummy load and power meter for HF (PDF)RFJun 24, 20150
Simple RIT circuit based on a 2N7000 FETRFSep 01, 20090
56K RF Modem circuit diagramRFJan 06, 20020
5 tubes SSB QRP Transceiver for 20m Ham bandRF 0
Kenwood TR-7950 manual & schematics (PDF)RFSep 10, 20060
Bug Duster - a detector for uncovering RF-based video and audio bugging devicesRFJul 10, 20150
Low Frequency Block Converter - Converts VLF/LF bands to shortwave frequenciesRFJul 10, 20150
Active antenna that will work from below a few kHz to over 100 MHzRFJul 10, 20150
Programmable PLL (Si570) Local Oscillator for HF Receivers, Transmitters, Transceivers (PDF)RFJul 13, 20150
All-purpose 0 - 30 MHz DDS VFO and Signal Generator based on the article by WB2V in QEX July, 1997.RFJul 13, 20150
DDS based Signal Generator that runs from 1Hz to 60MHz in 1Hz stepsRFJul 13, 20150