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Designing RF Probe - make your self simple and heighly useful RF probe. An essential tool for every home brewer.
Digital display & VFO stabiliser - Digital display & VFO stabiliser using a PIC microcontroller & LCD __ Designed by EI9GQ homebrew radio
Digital wireless for the bench top ATtiny12 - This section describes an experimental low power, low bandwidth data signaling system that was initially made to operate at 55 MHz (television channel 2 in the U. S.). Before operating a radio transmitter, find out what kind of transmitter operation, if any, is permitted in your locality. Radio transmitter operation is a serious legal matter. This design __ Designed by Dick Cappels
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 RadioV-U)HF AMPLIFIERSchematic __ Designed by Guy Roels ON6MU
Display RF Signal Strength - Many cordless telephones, computer networks and cell phones use a RF transmitter lefted on the 2.45GHz band. Using a microwave diode detector and 100uA meter, this passive circuit will display the strength this signal. The drawing shows how a bent piece of wire can be used as the antenna. . . . Hobby Circuit designed by David Johnson P.E.-July, 2006
DIY Cell Phone Charger - It seems that as cell phones become more sophisticated, their operating times become shorter and shorter. If you are on the go all the time and have difficulty finding AC or DC outlets to charge your phone, you might consider this simple scheme . . . Hobby Circuit designed by David Johnson P.E.-August, 2009
Do It Yourself Portable Cell Phone Charger - It seems that as cell phones become more sophisticated, their operating times become shorter and shorter. If you are on the go all the time and have difficulty finding AC or DC outlets to charge your phone, you might consider this simple scheme. . . Circuit by Dave Johnson P.E.-August, 2009
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 PICs; a PIC16F628A for the display, a PIC18F4520 as the main processor and a PIC12F675 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
Dual 6 to 1, 30 GHz RF switch matrix (Solid State) - This dual 6:1 RF switch matrix was built for a RF test system (Test and measurement application). The four layer PCB was designed with Coplanar waveguide over groundplane and Stripline techniques for very low sensitivity to manufacturing tolerances and very low assembly costs. One of the key tasks of the design was to carefully characterize the temperature performance of the matrix loss versus temperature so a loss correction versus temperature algorithm could be developed. __ Designed by Steve Hageman
Duplexer coupling loops & how they affect performance - An analysis of factory-built vs home-built loops, __ Designed by Kevin Custer W3KKC
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
Electronics enclosure heater - This is one of the more "Unique" designs that I have had the pleasure of doing. The client needed to keep an outdoor electronics enclosure from freezing during those long, cold winter nights in Fargo, ND. Originally silicone based heaters were to be used but the unregulated input power supply of 18-56 VDC would have meant that the heating rate would change by 100:1 from low line to high line input __ Designed by Steve Hageman
Enhance Week QRP CW with Stereo Processing - One of the biggest problems encountered when engaged in QSO with QRP stations is the weak signal strengths encountered. QRM and adjacent "QRO" stations can completely obliterate the weaker stations making them impossible to copy. But there is another "trick" we can use to "fish" the weaker stations out of the noise. Use our own sense of STEREO hearing. __ Designed by Harry Lythall-SM0VPO
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 DSB/CW QRP rig for 20 & 40 meter bands - The building of an HF phone rig today isn't shurely a simple job, however I'd like to propose an easytomake project, suited for portable or emergency use. As usual, some compromise must be accepted. Let's briefly consider good and bad points. __ Designed by Francesco Morgantini IK3OIL
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. |
