|
Ultrasonic switch transmitter & receiver The circuit described generates (transmits) ultrasonic sound of frequency between 40 and 50 kHz. As with any other remote control system this cirucit comprises of a mini transmitter and a receiver circuit. Transmitter generates ultrasonic sound and the receiver senses ultrasonic sound from the transmitter and switches on a relay __ Designed by Andy Wilson Ultrasonic transmitter & receiver - Presented here are the circuits of ultrasonic transmitter and receiver that use two CD4017 decade counters and ultrasonic transducers. __ Designed by PRADEEP G.
Ultrasound Receiver-40Khz - A X100 transistor amplifier is followed by a zero cross detector circuit, using a voltage comparator. The output is a TTL logic signal, corresponding to the received 40KHz signal . . . Hobby Circuit designed by David Johnson P.E.-January, 2006
Unidirectional RF wireless transmitting & receiving - Digital in, digital out, with no wires! ! ! Yes, it can be that easy but there are some things you will find out about going wireless that you may not have counted with wired connection. This App Note will guide you through a simple RS232 link and illustrate how easy these devices are to use as long as you know how to handle a couple wireless phenomenon and plan your project to take these into account. __ Contact info @ wzmicro.com
Universal Infrared Receiver - i think you know what's a UiR so iF it isn't so go to TiES BOS page and learn something :-). ! Briefly it's an infrared receiver which communicated with your pc to command many windows application, so once you have built the interface, programmed the pic16f84 with the code and connected everything to your serial com2 you'll be able to command your pc applications through your TV or VCR remote ! __ Designed by Alfred73
Universal USB digimode interface supports CAT (Yaesu), CI/V (Icom) & RS-232 (Kenwood) units - Microcontroller based electronic circuit __ Designed by Aleksander Stare
USB / CAT (CI-V) adapter tested with FT-8900, FTB-9800, VX-7R, VX-7, FT-817 & IC-706MkIIG - Schematic only, no circuit description included. __ Designed by Aleksander Stare
USB 0-500MHz RF Power Meter based on a AD8307 - Measurement of transmitter output RF power has never been easier and more precise. AD8307 USB 0-500MHz RF Power Meter allows to measure the power of transmitters from 1nW to 2W / 50W with 40dB attenuator. Output is displayed in dBm, Watts (nW, uW, mW and W range) as well as input voltage. USB RF Power Meter is based on popular AD8307 watt meter IC and PIC 18F2550 microcontroller. __
Valve Receiver with Automatic Regeneration - Based on the Radio & Hobbies "Three Band Two" this receiver has automatic regeneration control. __ Contact blehack @ yahoo dot com
Variable Bandwidth CW Filter - As the sunspots return and DX propagation conditions to improve, the age old problem with QRM begins to show up on the amateur bands. Fortunately, help is at hand. The circuit in figure 1 is a variable bandwidth CW filter using two IC 's. The first IC is a 741 op amp used as an active filter and the second IC is a 386 audio amp IC . This circuit connects to the headphone or speaker jack of your HF rig __ Designed by Radio Amateur Society of Norwich
Variable PIN Attenuator 1dB to 20dB - Schematic only __ Designed by va3iul
Versatile end-fed wire - A piece of wire of almost any length can be used as an antenna on the HF bands. However, just because an antenna can be made to work is no guarantee that it will perform efficiently. This article will initially concentrate on the half wavelength of wire and its useamateur radio construction projects. __ Designed by Peter Parker VK3YE
Very High Gain Crystal Earphone Amplifier - This simple, one-transistor amplifier provides a voltage gain over 1000 (60 dB) for driving a high impedance ceramic (crystal) earphone. The high gain is achieved by replacing the traditional collector resistor. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Very Simple Circuit ADSB Receiver using a TV tunder to allow reception of aircraft transponders - With this design you can expect to get several 100 km range with a good antenna. I use a home made J-pole with a single 32 Eurocent BFP420 transistor giving excellent low noise gain for very little money. it can be bought like most of the needed components at Reichelt. Many good quality (Kathrein for example) Satellite L band line amplifiers use this transistor and if you can get at least 12 Volts to the preamp they offer excellent performance despite being laid out for 75 Ohms. i'll document the preamp later. This is what you can get in Luxembourg with a clear view to the South for several kilometers __ Designed by Edward John Cardew
VFO from 2001 ARRL Handbook, page 14.20 - Schematic only __ Designed by Jim Osburn, WD9EYB
VFO from 2001 ARRL Handbook, page 17.74 - Schematic only __ Designed by Jim Osburn, WD9EYB
VHF 6 Meterband RF Amplifier - Ham Radio - AF Amplifiers - Schematic __ Designed by Guy Roels ON6MU
VHF Condor 16 transceiver modifications - Ham Radio - Other __ Designed by Guy Roels ON6MU
VHF FM TDA7000 Receiver - Very nice and simple design by Harry Lythall __ Designed by YO5OFH, Csaba Gajdos
VHF Receiver Converterer - For Q1 and Q2 I used a pair of 3SK45 dual gate FET's. Most VHF N-Channel dual gate MOSFETs should work fine. I have used 3SK88, BF961, and BF981 FET's in this circuit. if you decide to use a GaAsFET for Q1, you will probably need to use a Zener diode to reduce the drain voltage to a safe level. L1 is 5 turns of 1mm copper wire, tapped at 1 turn, coil diameter 7mm, L2 and L3 are 5 turns each. T1 primary is 9 turns on a Toko 10mm former (old iF transformer) T1 secondary is 2 turns. The screening can and outer ferrite cup are not used. __ Designed by EI9GQ homebrew radio
VHF Receiver for Weather Satellites - Build this compact 2-channel VHF FM receiver and pull in your own weather satellite pictures.__ SiliconChip
VHF/UHF Prescaler - The recommended Prescaler is ridiculously simple. it consists of just one IC , a TV tuner prescaler, the Philips SAB6456A, which can divide by 64 or by 256. This chip is widely available both new and in the surplus market at much lower prices than conventional divide by 10 prescalers. __
VHF/UHF TV Modulator - Simple oscillator that generates a frequency in the VHF or UHF region. The oscillator is modulated with the video signal and the modulated carrier wave thus generated is fed into the TV set's aerial input via a cable. Then all that remains to do is tune the TV to the correct frequency. __
Video emitter uses battery power - 08/30/01 EDN Design Ideas: The block diagram in Figure 1 shows how to make a cable-free, direct-video system. The system allows users to walk from booth to booth at an exhibition to interview people and to display the interviews in real time on three screens at key locations. You can use the small and simple system each time you need to capture image and sound on the run Design by JM Terrade, Clermont-Ferrand, France
VK5JST Aerial analyser - This project was published in the April 2004 issue of the Australian magazine "Amateur Radio", and has been designed using parts which are very readily available. Click here (AR June 2004 Article) to download the PDF file of the article. __ Designed by VK5JST / VK5TR
VLF Upconverter for Shortwave Receiver - The schematic above is a simple up converter which I used in conjunction with a short-wave receiver to quite successfully to monitor solar flare activity a few years ago. You can use a 3.5 or 4 MHz crystal for Y1 to up convert from about 10 KHz to 150 KHz to either 3.510 or 4.010 MHz respectively. A long wire antenna was used here but a VLF loop antenna __ Designed by Radio-Sky Publishing
VLF Whistler Reception - "Natural Radio" is a fancy name for radio noise with natural origins, mainly lightning. At first, you might think that listening to lightning crackles is pretty uninteresting but as it turns out, electromagnetic radiation from lightning can travel great distances and undergo strange modifications along the way __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Voltage to Frequency Converter + 1us LED Pulse Driver - This circuit receives the signal from the above amplifier and launches powerful 1uS infrared light pulses from a low cost LED that are frequency modulated by the audio information. The 10KHz center frequency of the pulse stream is low enough so a standard. . . Circuit by David Johnson P.E.-March, 1999 |
