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Oscillators:  RF (Radio Frequency)

Power Supplies -- Main Page       Oscillator Circuits -- Main Page
 

Last Updated: November 30, 2017 10:29 AM

Circuits Designed by Dave Johnson, P.E. :

175Khz Inductive Pulse Receiver - This circuit is discussed in more detail in the Experimenters Journal.  The receiver’s six inch diameter coil detects the ring signal from the above transmitter and use a single NPN transistor to provided enough amplification for the signal to be easily viewed on an oscilloscope. . . Circuit by David Johnson P.E.-June, 2000

240VAC to 5VDC Power Supply - This is simple way to power some 5v logic from a 240vac source.  If a 120vac power adapter is used, the circuit will also work for 120vac power lines. . . Circuit by David A. Johnson P.E.-February, 2002

CMOS Inverter Parallel LC Oscillator - I have used this parallel resonant LC oscillator circuit countless times.  The oscillator frequency is determined by the inductor and capacitor values.  I have shown an adjustable inductor to make it easy to set the frequency to a specific value. . . Circuit by David Johnson P.E.-March, 2002

Inductive Pulse Receiver (175Khz) - This circuit is discussed in more detail in the Experimenters Journal.  The receiver’s six inch diameter coil detects the ring signal from the above transmitter and use a single NPN transistor to provided enough amplification for the signal to be easily viewed on an oscilloscope . . . Hobby Circuit designed by David Johnson P.E.-June, 2000

Parallel LC Oscillator with CMOS Inverter  - I have used this parallel resonant LC oscillator circuit countless times.  The oscillator frequency is determined by the inductor and capacitor values.  I have shown an adjustable inductor to make it easy to set the frequency to a specific value . . . Hobby Circuit designed by Dave Johnson P.E.-March, 2002 

Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

10 MHz GPS Disciplined Oscillator (GPSDO) -  A unique feature of the Rockwell/Conexant/Navman Jupiter GPS engines is that they have a 10 kHz output, synchronized to GPS time.  So, with a few additional components one can phase lock a 10 MHz VCXO to the 10 kHz, and then have a simple low cost frequency standard with surprising performance __ Designed by James Miller G3RUH

13.8V 30-40A Power Supply -  Schematic only, a powerful power supply for my amateur radio equipment using four HEX FET transistors for regulation.  Text can be found at: http://www.agurk.dk/bjarke/Projects/PowerSupplyFET/PowerSupplyFET.htm __ Designed by Bjarke Korsgaard

175Khz Inductive Pulse Receiver -  This circuit is discussed in more detail in the Experimenters Journal.  The receiver’s six inch diameter coil detects the ring signal from the above transmitter and use a single NPN transistor to provided enough amplification for the signal to be easily viewed on an oscilloscope. . . Circuit by David Johnson P.E.-June, 2000

240VAC to 5VDC Power Supply -  This is simple way to power some 5v logic from a 240vac source.  If a 120vac power adapter is used, the circuit will also work for 120vac power lines. . . Circuit by David A. Johnson P.E.-February, 2002

Add phases to Simple Circuit RC oscillator -  08/25/14  EDN-Design Ideas - Demonstrates a simple way to generate a multiphase clock signal, the frequency of which can be varied with minimal change in phase shift (s).  The phase shift of the second output can be tuned from near zero to 180° without affecting the frequency.  The basic circuit uses a minimum of parts: one cap, two resistors, plus two Schmitt triggers.   __ Circuit Design by Einar Abell

Automatic Tuner-Transceiver Interface ATTI for IntelliTune MFJ-993 (TM) by OZ2BKK (updated 4'th of October 2005) -  PIC16F876 based circuit controlling the Yaesu FT-817, FY-857 and FT-897 from the IntelliTune MFJ-993 tuner (made in May 2005)  __ Designed by Bjarke Korsgaard

Basic RF Oscillator #1 -  This circuit switches a relay at dark via a Light Dependent Resistor or LDR for short.  The applications are numerous.  In my application, it switches on a light with an older type movement sensor and is mounted on the top corner of my workshop with the LDR facing upwards.  The Dark Activated Relay prevents that the light is triggered during daylight hours.  But, it can also be used to switch led-beacon lights for your driveway, or whatever __ Designed by Tony van Roon  VA3AVR

CMOS Inverter Parallel LC Oscillator -  I have used this parallel resonant LC oscillator circuit countless times.  The oscillator frequency is determined by the inductor and capacitor values.  I have shown an adjustable inductor to make it easy to set the frequency to a specific value. . . Circuit by David Johnson P.E.-March, 2002

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

DSP-10 transceiver project -  DSP-based 2m transceiver controlled by a Personal Computer (made in June 2001)  __ Designed by Bjarke Korsgaard

Inductive Pulse Receiver (175Khz) -  This circuit is discussed in more detail in the Experimenters Journal.  The receiver’s six inch diameter coil detects the ring signal from the above transmitter and use a single NPN transistor to provided enough amplification for the signal to be easily viewed on an oscilloscope . . . Hobby Circuit designed by David Johnson P.E.-June, 2000

Op-Amp Oscillators Simplify RF Design -  10/10/96 EDN-Design Ideas - Figure 1 shows a novel circuit that uses a low-cost, high-speed op amp as a crystal-controlled RF sine-wave oscillator.  An op-amp oscillator offers several advantages.  Because an op amp is a complete amplifier with a high-impedance input __ Circuit Design by Charles Kitchin, Analog Devices, Wilmington, MA

Parallel LC Oscillator with CMOS Inverter  -  I have used this parallel resonant LC oscillator circuit countless times.  The oscillator frequency is determined by the inductor and capacitor values.  I have shown an adjustable inductor to make it easy to set the frequency to a specific value . . . Hobby Circuit designed by Dave Johnson P.E.-March, 2002

PSK Meter (updated 4'th of October 2005) -  PSK-Meter is a controller board to prevent overload of a transmitted PSK-signal at the HF-bands (made in February 2004)  __ Designed by Bjarke Korsgaard

RF oscillator uses current-feedback op Amp -  10/03/02 EDN-Design Ideas - A current-feedback amplifier is a well-known component with many uses.  Its basic block diagram shows that its input stage is a voltage follower—in practice, a symmetrical emitter follower (Figure 1).  The configuration samples the output current, converts it to voltage across a large impedance, and amplifies it to the output using a high-power, low-output-impedance amplifier __ Circuit Design by Victor Koren, Tioga Technologies Ltd, Tel Aviv, Israel

Signal Frequency Beat Frequency Oscillator -  Timing and oscillator circuit diagrams / circuit schematics __ Designed by Peter Parker VK3YE

Supporter for my fiber glass antenna mast -  This is my Homebrewed fiber glass antenna mast supporter used for a 10 meter tall fiber glass antenna mast (made in May 2005)  __ Designed by Bjarke Korsgaard

Yaesu FT-897, FT-857 & FT-817 transceiver-PC interface (YFPI) -  This interface is used to fully control a transceiver, from a personal computer, when operating digital amateur radio modes (made in January 2006)  __ Designed by Bjarke Korsgaard


Oscillators:  RF (Radio Frequency)


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