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LF Regen - Experimental Building Notes - Anyone experimenting with the LF regen circuits described by Mike Tuggle and Roeloff Bakker in my recent "Tuggle-Style LF Regens" blog, might be interested in some helpful 'building notes' posted to the Yahoo ndblist by noted NDB/BCB DXer and exceptional RF guru, Steve Ratzlaff, AA7U of La Grande, Oregon. __ Designed by VE7SL - Steve
Light Sensing RF Transmitter - This transmitter is very simiilar to the Simplest RF Transmitter. The only difference being the photoresistor placed in series with R1. This could also be a thermistor or other variablwe resistance sensor. __ Designed by Tony van Roon VA3AVR
Linear FM 30Watt - A amplifier of medium force RF for the FM, is always essential for the amateur that wants it strengthens some small transmitter, that likely it has already it manufactured! The present circuit can give force 25-30W, with control no bigger than 4-5 W. __ Contact IQ Technologies
Line-Powered Xenon Flash Transmitter - This line powered xenon flash circuit drives a small camera type flash tube. it has an optical isolator to allow the flash to be safely triggered from some remote device. A flash rate of 2Hz is possible with the circuit. . . Circuit by David A. Johnson P.E.-June, 2000
Liquid Level Transmitter/Receiver System - designed for marine applications using raytheon's seatalk®bus. includes tachometer transmitter example although the receiver is only for liquid level (16f628) __ Designed by Jon Fick
Little Jim AM Transmitter - A Flea-Power Unit For The AM Broadcast Band__ SiliconChip
Locate a Plastic Pipe - I used this circuit once to track down the location of a plastic pipe, buried underground. it transmits a weak RF signal, which can be picked up by a portable AM radio from about 6 feet away . . . Hobby Circuit designed by Dave Johnson P.E.-December, 2004
Long Range FM Transmitter - This circuit is a circuit diagram fm transmitter. This circuit is somewhat different from the previous fm transmitter circuit. Transmitter circuit described here has the additional RF power amplifier stage, after the oscillator stage, to increase the power output of 200-250 milliwatts. With a good matching 50-ohm ground plane antenna or multi-element yagI antenna, this transmitter can provide a good enough signal strength to a distance of about 2 kilometers.__
Long Range FM Transmitter - The power output of many transmitter circuits are very low because no power amplifier stages are incorporated. The transmitter circuit described here has an extra RF power amplifier stage, after the oscillator stage, to raise the power output to 200-250 milliwatts. With a good matching 50-ohm ground plane antenna or multi-element YagI antenna, this transmitter can provide reasonably good signal strength up to a distance of about 2 kilometres. The circuit built around transistor T1 (BF494) is a basic low-power variable-frequency VHF oscillator. A varicap diode circuit is included to change the frequency of the transmitter and to provide frequency modulation by audio signals. The output of the oscillator is about 50 milliwatts. Transistor T2 (2N3866) forms a VHF-class A power amplifier. it boosts the oscillator signal power four to five times. Thus, 200-250 milliwatts of power is generated at the collector of transistor T2.__
Long Range FM Transmitter - The power output of many transmitter circuits are very low because no power amplifier stages are incorporated. The transmitter circuit described here has an extra RF power amplifier stage, after the oscillator stage, to raise the power output to 200-250 milliwatts. With a good matching 50-ohm ground plane antenna or multi-element YagI antenna, this transmitter can provide reasonably good signal strength up to a distance of about 2 kilometres __ Designed by Submitted Viswanathan Prakash 29-1-10
Long-Range FM Transmitter - Several circuits for constructing FM transmitters have been published in EFY. The power output of most of these circuits were very low because no power amplifier stages were incorporated. The transmitter circuit...__ Electronics Projects for You
Long-Range IR Transmitter - Most of the IR remotes work reliably within a range of 5 metres. The circuit complexity increases if you design the IR transmitter for reliable operation over a longer range, say, ...__ Electronics Projects for You
Loop powers current transmitter - 10/28/99 EDN Design ideas: in the circuit in Figure 1 , the loop supply is 20 to 30V dc, and the loop current is 10 to 20 mA. IC 1 operates as a constant-current (I P) source. IC 2 , R 1 , and R 2 operate as a shunt regulator, which provide as 12V V CC . IC 2 is a TLO32 op amp. The sensor circuit could be a resistance-temperature-detector circuit or any other sensor- or signal-conditioning circuit. Design by N Kannan
Low Frequency Phasing Exciter - As of this writing, two programs are available for data transmission at low frequencies that use a computer sound card and output the audio in an i/Q format. JASONhas a unique FSK format with a variety of data rates. The "DigiMode Terminal" in Spectrum Laboratorygenerates PSK and MSK signals suitable for LF work. if you are new to all of this, check out the Low Frequency Transmission Mode article on this site __ Designed by John K. Andrews Holden, MA FN42ch w1tag @ charter.net
Low Pass Filter for FM 88-108 MHz - Filter used for eliminate unwanted harmonic frequency at second and third. Notch filter, Band Pass Filter (BPF) , and High Pass Filter (HPF) sometime combined in constructing LPF design. Schematic below for FM Broadcast Lowpass Filter 88-108 MHz__
Low Power AM Transmitter - This "phono oscillator" design transmits over a suprising distance and uses only two valves. __ Contact blehack @ yahoo dot com
Low Power FM Transmitter - Useful to retransmit the hi-fI to another FM receiver nearby, or as a wireless mic __ Designed by Rod Elliott ESP
Low Power FM Transmitter - This low power fm transmitter is designed to use an input from another sound source and transmits on the commercial FM band. This low power fm radio transmitter it is actually quite powerful. The first stage is the oscillator, and is tuned with the variable capacitor. Select an unused frequency, and carefully adjust C3 until the background noise is removed.__
Low Power PLL FM Transmitter based on LMX1601 & Atmel ATtiny2313 or AT90S2313 microcontroller - An LMX1601 Phase locked loop, a discreetFET VCO, and an AVR micro controller combine to make a stable, easy to use monophonic FM transmitter that includes a an audio activated switch that turns the transmitter on only when its being used __ Designed by Dick Cappels
Low-cost relative-humidity transmitter uses single logic IC - 11/08/01 EDN Design ideas: The low-cost percentage-relative-humidity radio transmitter in Figure 1 operates in a cold-storage warehouse for vegetable storage at temperatures of 1 to 5°C. it is generally difficult to collect such data from a low-temperature area with high humidity and low illumination. The transmitter design is simple it uses a readily available, capacitor-type percentage-relative-humidity se Design by Shyam Tiwari, Sensors Technology Ltd, Gwalior, India
LowPass Filter - The schematic you find here comes from another site on the internet, but because it's on so many sites, we don't know who actually designed it. However it's a nice one. Capacitors: C1, C4 22pF cer. C2, C3 51pF cer. Coils: L1, L2, L3 #18 bus wire, 1/4"diameter, 3 turns * Form the leads from the capacitors as shown in the little figure below. Then solder them from the pad to the outside ground area. * Be sure that the turns from the coil are seperated by the same distance as the diameter of the wire * Form the leads from the coils as shown in the little figure below. Then solder them in place. * Place the filter in a metal box, with rf-connectors on both ends (SO239 (=PL259) , BNC or N-connectors) __
Low-Range AM Radio Transmitter - Here is a simple radio transmitter for transmission up to 25 metres. it is basically an AM modulator whose signal can be received on the normal AM radio. it can also...__ Electronics Projects for You
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