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TDA7000 Receiver - Philips Semiconductors App Note 193in cordless telephone sets, a normal superheterodyne receiver is used for the 1.7MHz handset. The suppression of the adjacent The ceramic iF filter with itssubharmonics is bad for far-off selectivity, so there must be an extra LC filter added between the mixer output and the ceramic filter __ Designed by W.V. Dooremolen Telephone Line Filter / Protector - To build a circuit that will help protect your equipment from lightning strikes on the phone line. This circuit was actually designed to reduce or eliminate a very local broadcast AM radio stations signal from bombarding my parents telephone line, however it also turned out to be a really good lightning protector. __ Designed by Kevin Custer W3KKC
Telephone Receiver - This simple telephone receiver without a dialling section can be connected in parallel to a telephone line. it can be easily assembled on a small vero board or a PCB. A...__ Electronics Projects for You
Temp Indicator (Window Comparator) - A window comparator usually employs 2 comparators with one output indicating the input is somewhere between two limits. in these examples, a third comparator is added to display all three conditions where the input is in the center range, or higher, or lower. __ Designed by Bill Bowden
Tesla Power Receiver - Here's something that has always bugged me: light waves are about 5000 Angstroms in wavelength, while atoms are more like 1 Angstrom across. Atoms are thousands of times smaller than light waves, yet atoms obviously interact very strongly with light. How can they do this? Perhaps they get around the problem by employing Quantum Mechanics (photon-physics rather than EM waves?) There must be some explanation. __ Designed by William J. Beaty
The AA8V Twinplex Regenerative Receiver
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After building several simpler receivers, I wanted to try my
hand at a more complicated, multi-band, multi-stage, receiver.
Someday I wanted to build a superhet, but I thought I should try
building a really good regenerative receiver first. [Designer:
Greg Latta, AA8V]
The ADC-40 - All Discrete Components 40 M transceiver with super-het receiver using no IC 's, just a whole bunch of transistors of various flavors (NPN, PNP, J-FET, MOSFET) __ Designed by Steven "Melt Solder" Weber KD1JV
The AM azing All Band Receiver - The Amazing All-Band Receiver is basically a diode detector followed by a high-gain audio amplifier. This is not a multi-band receiver; it picks up everything at once! The detector uses a biased Schottky diode for excellent sensitivity and bandwidth; the detector will detect signals from below the AM broadcast band up to the microwave bands. The number of interesting signals is surprising; it is fun to drive around listening to the numerous strange sounds. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
The ATL-3 Loop Antenna - All ATL-3 loop windings are centre tapped and balanced w. r. t. their amplifier/receiver chassis ground, and therefore electric field interference pick up tends to self cancel. Magnetic noise fields, e. g. televisions and the electric meter box, or __ Designed by Graham Maynard
The Countersurveillance Monitor - Figure 1 shows a schematic diagram of the Countersurveillance Monitor. The circuit, built around a single integrated circuit (U1. an MC3403P quad op-amp) , three transistors (Q1-Q3) , and a few support components, receives its input from the antenna (ANT1). That signal is fed through a high-pass filter, formed by C1, C2, and R1, which eliminates bothersome 60-Hz pickup from any nearby power lines or line cords located in and around buildings and home. __ Designed by Vincent Vollono and Tony van Roon
The Jet Propulsion Laboratory-"Smart VOX" - For creating a COS signal from a radio that doesn't have one. This circuit was developed to control the retransmission of NASA Select audio over JPL's W6ViO repeaters. __ Designed by Randy Hammock KC6HUR and Jan Tarsala WB6VRN
The Journey to Forever--Crystal Radio - You can make a crystal set out of almost anything -- any small box, or just a bit of wood, or a frisbee or a deodorant dispenser (actual examples) , or these (recommended for beginners) : __ Designed by Keith Addison
The KØLR LF Antenna Meter - if you plan to become active on Canada's new 630m ham band, one of the first things you're probably thinking about is an antenna and how to make it resonant. Without the proper instruments, determining antenna resonance below the broadcast band can sometimes require a combination of good luck and black magic! __ Designed by VE7SL - Steve
The MMR-40 - Winner of the ARRL Homebrew challenge, non-PC option category. A 40 meter CW/SSB transceiver using less than $50.00 in parts. How to build "dead bug" style. __ Designed by Steven "Melt Solder" Weber KD1JV
The Moorabbin regenerative AM receiver - amateur radio construction projects. __ Designed by Peter Parker
The MRX 40 Mini Receiver - After exploring very low power (QRPp) communication by building a 40 meter Micronaut CW transmitter, 1 I took on the challenge of constructing a tiny 40 meter companion receiver. Not only did I think the receiver would complement the Micronaut, I thought it might also have potential as a kit project for my hometown group, the CQRP (Columbus, Ohio, QRP) Club. The final push to action came from the discovery that there were 93 licensed amateurs in my neighborhood ZiP code __ Designed by Steve Bornstein, K8IDN
The Repeater Builder's Friend - A device to help to you fix your repeater or program your controller __ Designed by Matt Krick K3MK
The SID Seizer-monitor SIDs - The SiD Seizer is a VLF/LF receiver project for monitoring Sudden ionospheric Disturbances, typically caused by solar flares. This article assume the reader has basic knowledge of the effects of solar flares on the ionosphere. (A web search will yield a wealth of information on SiD reception, including other simple designs, typically employing loop antennas.) Breaking with tradition, the SiD Seizer uses a vertical whip antenna with a tuned amplifier, instead of a tuned loop. My house and neighborhood have so much magnetic noise that a vertical whip antenna is significantly superior to a loop. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
The UnFETtered Crystal Radio! - Several weeks ago I became aware, via the internet, of an experimental AM 'crystal set' style of receiver, that uses what is known as a ZVB (Zero Voltage Bias) device. This is in the form of an IC , which contains either a 2 pack or 4 pack of specialised FETs (Field Effect Transistors) that require no bias voltage on their gates to conduct current from source to drain. They simply rely on signal voltages to turn them partially or fully on. This new IC , dubbed the ALD110900A, is made by Advanced Linear Devices __ Designed by Austin Hellier © April 2007 |
