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Amplifier Circuits: 
RF (Radio Frequency)

RF Amplifiers:  #'s - C      D - K        L - R       S - Z

Amplifier -- Main Page
 

Last Updated: November 21, 2017 05:44 AM

Circuits Designed by Dave Johnson, P.E. :
characteristics of CMOS Logic Inverter Amplifiers -  This chart shows some of the measured characteristics of three different unbuffered CMOS logic gates, used as voltage amplifiers . . . Hobby Circuit designed by David Johnson P.E.-February, 2002

CMOS Logic Inverter Amplifier characteristics -  This chart shows some of the measured characteristics of three different unbuffered CMOS logic gates, used as voltage amplifiers. . . Circuit by Dave Johnson P.E.-February, 2002

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

Cascode 7 Experimental Receiver -  Many amateur experimenters stay in the familiar comfort zone of HF.  A small number venture into VHF, and even fewer devote time designing, building and operating for the UHF & microwave spectrums.  

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 A. Johnson P.E.-August, 2009

Cell Phone Solar Powered Charger -  The simple circuit below regulates the voltage from a 6v solar panel to a fixed +5v.  That voltage can be fed to any cell phone or USB connected portable device, to charge its battery.  The circuit uses a Reg113-5 voltage regulator from Texas Instruments . . . Hobby Circuit designed by David A. Johnson P.E.-January, 2011

Ceramic Filter BFO -  Receive SSB and CW transmissions on your BC receiver.  Simple BFO is build around 455 KHz Ceramic Filter

CH-25 Crystal Heater Kit -  As above with professional circuit board __ Designed by Kevin Custer  W3KKC

characteristics of CMOS Logic Inverter Amplifiers -  This chart shows some of the measured characteristics of three different unbuffered CMOS logic gates, used as voltage amplifiers . . . Hobby Circuit designed by David Johnson P.E.-February, 2002

Cheap Crystal filter -  Ladder filter using six 4.43MHz Crystals.  Building cheap side band filter for your bome brew SSB Rig

Cheap radio frequency plasma generator -  This page details how a RF plasma source of approximately 1 kW can be constructed from house-hold materials.  Possible uses include plasma cleaner, plasma etch, remote activation species generation and no use at all (my personal favorite). __ Designed by Greg Miller

Class B series Modulator -  Schematic only__ Amfone.net

CMOS Logic Inverter Amplifier characteristics -  This chart shows some of the measured characteristics of three different unbuffered CMOS logic gates, used as voltage amplifiers. . . Circuit by Dave Johnson P.E.-February, 2002

Collection of Crystal Radios -  Collection of Crystal Radio Circuits __ Contact: Charles Wenzel of Wenzel Associates, Inc.

Compact 25 GHz Fractional N, PLL Synthesizer  -  12002500 MHz RF Source subassembly.  The design consists of: Fractional N PLL, modular VCO, Dividers, RF harmonic filters, AGC leveling loop, and output amplifiers.  The 4 layer PCB was designed with Coplanar waveguide over groundplane and Stripline techniques for very low sensitivity to manufacturing tolerances and very low assembly costs. __ Designed by Steve Hageman

Complete 30 GHz Fractional N, PLL Synthesizer / source  -  7503000 MHz RF source subassembly.  The design consists of: Fractional N PLL, discrete VCO, Dividers, RF harmonic filters, precision AGC leveling loop, and output amplifiers.  The 6 layer PCB was designed with Coplanar waveguide over groundplane and Stripline techniques for very low sensitivity to manufacturing tolerances and very low assembly costs. __ Designed by Steve Hageman

Constructing Scotty Sprowls' 1 GHz RF Spectrum Analyzer -  This is a series of notes and videos on constructing the 1 GHz RF spectrum analyzer project by Scotty Sprowls. __ Amateur Radio circuits from Green Bay Professional Packet Radio

Construction Details for 30 meter rig with superhet receiver & crystal controlled transmitter -  For the spring 2010 FDIM (Four days in May) design contest, the ARCI (Amateur Radio Club International) decided on seeing if anyone could design a rig using 72 or less parts.  What made this design a challenge was the fact the rig had to be a transceiver, the receiver had to have single signal reception and only 1 IC could be used.  The design goal of my version was to come up with a reproducible design, using all common, easy to get and inexpensive parts.  It also had to have a reasonably sensitive receiver and a transmitter with a bit more than flea power output. __ Designed by Steven Weber, KD1JV

Controlling TDMA Timeslot Power Levels using the Esg-D Series, RF Signal Generators -  Application Note__ Aligent

Convert 2m VHF FM PMR transceiver Motorola Radius M110 into an AM ateur radio -  Turn a professional 2m VHF FM PMR transceiver Motorola Radius M110 into an amateur radio __ Designed by Aleksander Stare

Converter to Hear AM ateurs on your FM Radio -  If you're the sort who'd like to have an HF receiver in every room, but can't afford it, this idea is for you.  It will also appeal to the beginner wishing to build the simplest possible direct conversion receiver.  Using a readily-available FM wireless microphone kit, it is possible to broadcast the audio output of a homebrew direct conversion receiver around your property and beyond. __ Designed by Peter Parker VK3YE

Converter to yune six metres on your two metre receiver -  If you're the sort who'd like to have an HF receiver in every room, but can't afford it, this idea is for you.  It will also appeal to the beginner wishing to build the simplest possible direct conversion receiver.  Using a readily-available FM wireless microphone kit, it is possible to broadcast the audio output of a homebrew direct conversion receiver around your property and beyond. __ Designed by Peter Parker VK3YE

COR Carrier Delay timer / Hang Timer -  Did you ever want a simple controller to key a transmitter from a receiver's cos?    Well here is a simple circuit that does just that.  The input impedance is fairly high, about 1 Meg, and will interface to most any receiver.  VR 1 is a sensitivity control that is adjusted to trigger the circuit with just about any available positive going signal.  A setable hang time is adjusted with VR 2. __ Designed by Kevin Custer  W3KKC

Cordless Phone Backup -  Normally the base of a cordless phone has an adaptor and the handset has Ni-Cd cells for its operation.  The base unit becomes inoperative in case of power failure.  Under such__ Electronics Projects for You

Crystal heater / temperature stablization (TXCO) -  OK, here is the circuit I usedSee image below.   The original National Semiconductor circuit had a 30 K resistor in series with a 400 F cap., both in parallel with the 100 K resistor on the input of the 1st LM324 section.   I found that combo to actually destabilize the operation of the controller for this particular application, so I removed them & changed the 2 F cap in series with the 10 megohm resistor to 5 F. __ Designed by Bob Dengler NO6B

Crystal Radio -  RF Receivers & Receiver Circuits Crystal Radio __ Designed by Aaron Cake

Crystal Radio -  I have been listening stories from dad that he made a radio when he was little younger than me.  It was hard to digest that his radio worked without power! I thought, its nothing more than those interesting old stories that we have been told at bed time!! __ Designed by Nina Gajjar

Crystal Radio -  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 -  This is a generic circuit, the first true radio receiver in history.  Description: Crystal radio requires no power supply to operate because it uses energy from the signals it receives.  Performance is like one should expect poor.  Nevertheless, __ copy of geocities.com/tomzi.geo page

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 

Crystal Radio--make your own -  Circuit Only __ Designed by Charles Wenzel

Crystal switcher using diodes -  Schematic only, no circuit description __ Designed by Guy Roels ON6MU

CW Beacon Keyer -  This circuit stores a morse code message as bits in an EPROM chip, the message controls a relay that keys a CW (morse code) transmitter.  An Arduino processor can also be used in place of this circuit, that eliminates the need to build the circuit and program an EPROM. __ Designed by G. Forrest Cook

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RF (Radio Frequency) Amplifiers:  #'s - C      D - K        L - R       S - Z


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