|
Designing an AM Receiver for Low Power Wireless Systems using the NEC UPC2768GR IC 7/22/96 - App Note Doc #921__ California Eastern Laboratories
Detector Lightning - A VLF receiver tuned to 300 kHz designed to detect the crackle of approaching lightning. A bright lamp flashes in synchrony with the lightning bolts indicating the proximity and intensity of the storm. it has a superior RF section with a single resonance near 300kHz and plenty of sensitivity. The antenna is a telescopic antenna that extends to two or three feet __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Detrola 297 Car Radio - Unusual U. S. made car radio from 1940. Very compact one unit construction. __ Contact blehack @ yahoo dot com
Digital Amateur Callsign sender/reciever with selective call - 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
Digital Automatic Gain Control AGC - This project is a digital Automatic Gain Control (AGC) system using a PIC 16F876 MCU. The ability to set the gain level in a circuit and have it control itself is a very useful function. This circuit is a building block of another project I am working on. A 30W power amp for either the PCS, iDEN or CDMA frequency bands. I will settle on one of those frequencies sometime soon. __ Designed by steevn.geo @ yahoo.com
Digital display & VFO stabiliser - Digital display & VFO stabiliser using a PIC microcontroller & LCD __ Designed by EI9GQ homebrew radio
Digital Radio Mondiale (DRM) - Modification of my Yaesu FT-897 transceiver and building of a 467 kHz iF mixer to make a complete working DRM receiver system (made in the beginning of 2005) __ Designed by Bjarke Korsgaard
Digital VLF Receiver - DDS Synthesized VLF Receiver __ Designed by Steve Hagerman
Digital Wattmeter, measures from nanowatts to kilowatts using AD8307, PIC16F876, LCD Display - The extra input B is for a later SWR brigde project, also the TX serial output will be in use later. The uncalibrated signal response is: +1/-1 dB from 1MHz to 450MHz. input SWR vill varry from 1.00 to 1.30, depending on input frequency. To make the SWR this good, you need to assemble the input circuit correct and adjust the capasitor. input power range: -60 to +30dBm that is 1 nW to 1 Watt. __ Thomas Scherrer OZ2CPU
Direct conversion 7MHz receiver using NE602 - Schematic only, no circuit description__
Direct Conversion Receiver for Radio Amateurs-Part 1 - it covers from 7-7.3MHz, can tune both morse and SSB signals and reads out the tuned frequency in morse code! __ SiliconChip
Direct Conversion Receiver for Radio Amateurs-Part 2 - This article has the full construction and alignment details. We also include tips on using it.__ SiliconChip
Direct Crystal radio receiver examples - Ham Radio - V-U) HF AMPLiFiER - Schematic __ Designed by Guy Roels ON6MU
Direct MW/sw Radio RECEIVER - Ham Radio - V-U) HF AMPLiFiER - Schematic __ Designed by Guy Roels ON6MU
Direction Finder System - Similar to the system used in modern aviation where an antenna array modulates the phase of an incoming signal. The commercial system is known as Commutated Aerial Direction Finding (CADF) where a ring of 18 identical antennas are each switched on in sequence, just like winding a rotary switch round and round so that one antenna is always connected to the receiver. __ Designed by Harry Lythall-SM0VPO
Dirt-Cheap, High Current Power Supply - Here's yet another use for that pensioned-off AT computer that's gathering dust in the corner.__ SiliconChip
DIY Dual Directional Coupler, 5-1000 MHz, 20 dB - This is not a new invention. it's just a hack together of some (very) nice parts. And the result is an 'even nicer' part. (So we think :-) __ Designed by Alexander C. Frank, aka Ajarn Changpuak
DIY remote control based on PIC - Control up to 8 devices by this easy constructable remote control. it can work as a radio or infrared remote control, depending on the components. Each device output can be configured to be momentary (turned on while you press the button) or latched. Latched outputs can be toggled on/off by one button per channel, or turned on and off by two buttons per channel __ Designed by Peter Jakab
Dog Warden - a simple radio transmitter and reciever to signal when a dog has strayed too far __ Contact P. Townshend - EduTek Ltd
Doodle Labs DL435-30 420-450 MHz OFDM Transceiver Experiments - Experimenting with high-speed data in the 440 MHz ham band. __ Amateur Radio circuits from Green Bay Professional Packet Radio
Dopler RDF (radio direction finder) - 36 LEDs display; center LED when green = good signal, when red = no signal , the direction is frozen to the last good signal. - Uses 3 PIC s; a PIC 16F628A for the display, a PIC 18F4520 as the main processor and a PIC 12F675 as a frequency divider. - Filters; a Max 267, the best bandpass filter that I have ever seen, followed by the Roanoke switch cap filter for very narrow band width (+/- 0.5Hz). - My Dopplerii integrating and phase detection software in the main PIC . - LM386 for monitoring the audio independently from the doppler. __ Designed by Jacques VE2EMM & Claude VA2HDD
DSP-10 transceiver project - DSP-based 2m transceiver controlled by a Personal Computer (made in June 2001) __ Designed by Bjarke Korsgaard
DTMF RECEIVER - Today, most telephone equipment use a DTMF receiver IC . One common DTMF receiver IC is the Motorola MT8870 that is widely used in electronic communications circuits. The MT8870 is an 18-pin IC . it is used in telephones and a variety of other applications. When a proper output is not obtained in projects using this IC , engineers or technicians need to test this IC separately. A quick testing of this IC could save a lot of time in research labs and manufacturing industries of communication instruments. Here’s a small and handy tester circuit for the DTMF IC . __
Dual Mode Superhet/Direct Conversion AM receiver for 181.818 kHz Lowfer ATtiny2313, AT90S2313 - This is a description of an experimental AM receiver for VLF. it is crystal controlled to receive 181.818 kHz (more or less) and operates as either a single conversion superhetrodyne or a direct conversion receiver. The bandwidths are expected __ Designed by Dick Cappels
Dual-Mode Whistler Receiver - This portable receiver may be completely powered by a recorder or other device designed to use button microphones or it can use its internal battery to provide headphone listening. I decided to see if I could increase the values on the notch filter like that used in the computer-powered receiver above by nearly a factor of 10. Since this receiver will be able to __ Contact: Charles Wenzel of Wenzel Associates, Inc.
DVB compliant IP gateway - This project is now well under way and works fine. The modulator which will do DVB-S (QPSK with viterbi and RS) is still being developed. The gateway uses a Linux PC with a SLiP connection as a source and will modify the data to encapsulate it using the DVB mechanism so it can be received with commercial satellite receiver cards. PMT, PAT and SDT tables are transmitted as well so the data stream can be scanned by the receiver. __ Designed by Edward John Cardew
Easy FM Keyer - Many no code Technician class amateurs who are struggling to learn 5 WPM code simply do not have any avenue to get the necessary on the air practice. Figure 1 is a simple circuit which will generate a 700 Hz tone into any FM transceiver allowing an amateur to practice CW with another amateur on a 2 meter simplex frequency __ Designed by Radio Amateur Society of Norwich
Eclairs Receiver - Schematic + info __ Designed by Lennie Zink
Eclairs Receiver Accessories #1 - Schematic + info __ Designed by Lennie Zink
Eclairs Receiver Accessories #2 - Schematic + info __ Designed by Lennie Zink
Eclairs Receiver Accessories #3 - Schematic + info __ Designed by Lennie Zink
Eclairs Receiver Accessories #4 - Schematic + info __ Designed by Lennie Zink
Electronic Eavesdropping Devices Detector - Copyright of this circuit belongs to smart kit electronics. in this page we will use this circuit to discuss for improvements and we will introduce some changes based on original schematic. __ Contact IQ Technologies
Emerson CF255 - Two valve TRF midget set from 1939 __ Contact blehack @ yahoo dot com
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
Experimental fiber optic receiver - Schematic Only__
Experiments with Detector Diodes - When building crystal radios or other simple receivers, the experimenter often wonders about the relative performance of the different diodes in the junk box. Here are the results of several experiments using the typical. __ Contact: Charles Wenzel of Wenzel Associates, Inc. |
