750 MHz Power Doubler & Push-Pull CATV Hybird Modules using Gallium Arsenide 3/21/96
App Note Doc #920 __ California Eastern Laboratories
900-Mhz Down Converter Consumes Little Power
06/22/95 EDN-Design Ideas Most 900-MHz down-converter designs are proprietary and, thus, are unavailable to the industry. The designs that are available are usually discrete or require high voltage, which excludes them from the portable market. The down converter in Fig 1 is nonproprietary and suits battery-powered applications. Moreover, you can use the IC__ Circuit Design by Ronald Mancini and Raphael Matarazzo, Harris Semiconductor, Melbourne, FL
A 2320 MHz to 144 MHz RX Converter (old)
Older designnot recommended, description with schematics for the LNA and the Mixer. __ Designed by Herbert Dingfelder
A 50 MHz to 28 MHz RX Converter
Circuit description in English and in German, a picture of the circuit and the schematic diagram. __ Designed by Herbert Dingfelder
A programable 2.3-2.4GHz to 144 MHz Receiver-Converter (new)
A simple but well working design, a complete description with schematics and pictures. __ Designed by Herbert Dingfelder
AC power measurement uses PWM & PAM
EDN-Design Ideas 06/17/2015 Use clever pulse modulation techniques to multiply signals and measure power.__ Circuit Design by Adolfo Mondragon
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
Clock multiplier circumvents PLL
05/13/99 EDN-Design Ideas Using a standard PLL circuit, such as the CMOS
4046B with some passive components, is a wellknown way to design a clock multiplier. Unfortunately, using a PLL in a digital circuit has two disadvantages: It takesPDF contains many circuits, scroll to find this one. [Jose Carlos Cossio, Santander, Spain]circuit has two disadvantages: It takesPDF contains many circuits, scroll to find this one.__ Circuit Design by Jose Carlos Cossio, Santander, Spain
RF PLL Sythesizer
Synthesizer based on available CD4059. CD4046 and CD4060 ICs. __ Designed by Harry Lythall-SM0VPO
Cockcroft Walton Diode Voltage Multipliers
These circuits generate high voltages and can cause dangerous shocks! Do not build these devices unless you are experienced and qualified to work on high voltage devices. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Control Frequency Response & Noise In Broadband, Photodetector, Transimpedance Amplifier
EDN-Design Ideas 07/04/96 Converting the current output of a wideband photodetector to a voltage, minimizing noise, and achieving the desired frequency response can tax the patience of even an experienced designer. Careful selection and correct application of an op amp can often provide the best and most cost-effective solution. Choosing and properly applying a transimpedance amplifier for broadband photodetector applications involves understanding trade-offs. Manufacturers of components for wideband transimpedance applications often spec products only for selected detector diodes. These components can be prohibitively expensive for all but the narrowest applications.__ Circuit Design by Michael Steffes, Burr-Brown Corp
The crystal radio gets its name from the galena crystal (lead sulfide) used to rectify the signals. A "cat's whisker" wire contact was moved about the surface of the crystal until a diode junction was formed. The 1N34A germanium diode. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Crystal Radio RF Amplifier
One of the best places to add a transistor to a simple crystal radio is at the front end in the form of an RF amplifier. The circuit below is a simple but effective amplifier which will give surprising performance improvement. This amplifier __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Crystal Radio Set Version 2
This uses a more standard ceramic / crystal earpiece and LT44 transformer that you can buy easily. Look out though, this is a draft version. __ Designed by Henry
Delay Line implements Clock Doubler
Timing delays are undesirable in most digital circuits. However, in some cases, delays can be useful—to deal with a µP-speed-compatibility issue, for example. The circuit in Figure 1a uses a silicon T/4 delay line and an XOR gate to implement a simple clock doubler. Using a 5-nsec delay unit, a 50- MHz, 50% duty-cycle square-wave input produces a 100-MHz, 50% duty-cycle output clock. Using a more precise delay line, the circuit can output a triple clock (Figure 1b).__ Circuit Design by Y Li, SAE magnetics HK Ltd, Guang Dong Province, China7/18/96
Diode Frequency Doublers
Ordinary fast switching silicon diodes, special fast recovery junction diodes, schottky barrier diodes, varactors and even old-fashioned germanium diodes or vacuum tubes may be used to construct signal powered frequency doublers __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Dither a power converter's operating frequency to reduce peak emissions
10/13/05 EDN-Design Ideas Add a small circuit to spread the peak RFI energy__ Circuit Design by Bob Bell and Grant Smith, National Semiconductor, Phoenix, AZ
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.
Frequency divider with CD4017 __
Frequency Divider Adapts to I/O Condition
12/05/96 EDN-Design Ideas The circuit in Figure 1 accepts an input clock signal, such as from a crystal oscillator, and divIdeas the frequency according to the input divisor word. You can easily modify the basic design of this versatile PLD-based divider to handle different I/O conditions. The design uses the FLEX8000 family of PLDs from Altera Corp (San Jose, CA).__ Circuit Design by Steve Hranilovic, University of Waterloo, Waterloo, ON, Canada
Frequency Divider using 7490 Decade Counter
Here is a low-cost circuit for generating different square-wave signals. The circuit is built around a 10MHz crystal oscillator, hex inverter IC 7404 and seven decade counter ICs 7490. IC 7490 is...___ Electronics Projects for You
Frequency Doubler Operates On Triangle Wave
03/14/96 EDN-Design Ideas Frequency multipliers typically work with square waves. However, the circuit in Figure 1 performs frequency multiplication on triangle waveforms and maintains the input's amplitude and uniformity. The general idea is to apply the triangle waveform to any full-wave rectifier. The output is then a triangle wave with twice the input frequency plus some dc bias. You then can remove the dc bias using a simple highpass filter or by shifting the bias level with another op amp. You can continually repeat this trick to obtain a frequency series of 2xFIN, 4xFIN, 8xFIN, and so on.__ Circuit Design by Alexander Belousov, Standard Motor Products, Rego Park, NY
Frequency multiplier improves line readings
EDN-Design Ideas March 26, 1998 [ NOTE
: File has multiple design, scroll for this one.] Because of the low frequencies involved, accurately measuring line-frequency variations is complicated. When you use an ordinary frequency counter with a 1-sec gate time, the reading would be 59, 60, or 61 Hz. To obtain 0.01-Hz accuracy, you must increase the gate time to 100 sec, a scale that most frequency counters do not offer.__ Circuit Design by Yongping Xia, Teldata Inc, Los Angeles, CA
Frequency Tripler Using the CA3028
Here is a simple frequency tripler using a CA3028 differential amplifier. The CA3028 has internal bias resistors for setting the differential amplifier's current at about 7 mA when connected as shown. With this current, the output level is about 0 dBm at 30 MHz with a 1v p-p, 10 MHz input. __ Contact: Charles Wenzel of Wenzel Associates, Inc.