RF Transmitter Circuits
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This is schematic of a synthesized PLL for the Low Power FM transmitter. By the way, you also can use it with other circuits, just pay attention to recalculate the loop filter response and components, VCO tank circuit, and the correct thumbswitch programming.... -
A low power fm pirate radio. The output power is around +35 dBm ( 3. 16 watts) over 50 ohms load and +24 volts power supply. The project consists in a hartley oscillator ( modulated VCO), and tree stages ( Class A, common emitter) of RF amplifiers. The first.... -
The TV transmitter we present today generates a stream containing four TV programs and broadcasts it on a frequency in the DTT standard. Ideal for stacking in an antenna system, audiovisual channels generated on-site or from other sources like a decoder for.... -
The telemetric physiologic monitors transmit measurements of bodily functions from beneath the skin of a live animal to a receiver beneath the animal`s cage. The smallest transmitters the company makes, are their " mouse " transmitters. These were of.... -
Developing a transmitter small enough to be implanted in the body of a rat, fast enough to transmit four hundred sixteen-bit data samples per second, powerful enough to be detected at a range of three meters, and efficient enough to operate for three months.... -
The Subcutaneous Transmitter (A3013) transmits biometric signals from within the body of a live animal. It is the implantable transmitter component of our Subcutaneous Transmitter System. The A3013 detects biometric signals with flexible 150-mm leads,.... -
The Test Transmitter (A3020) is a combination of three circuits. Its purpose is to allow us to test the Subcutaneous Transmitter ( A3019 ) and to investigate SAW (surface acoustic wave) VCOs (voltage-controlled oscillators). The A3020 contains the complete.... -
In many discussions of LPAM transmitter design you will hear or read references to "the Wenzel circuit" or "the Wenzel transmitter. " These refer to the clever transmitter design downloadable at During the mid 1990s and early 2000s, this was the best.... -
Here is the circuit for the FM Bug. In total there are 18 core components that are needed for the fm transmitter to work properly. The far left side has the electret microphone and then things move electrically to the right until they hit the antenna. Don`t.... -
The schematic for this project is actually deceivingly simple compared to the complexity of what is happening in the circuit. So take a look below or click to view the full sized schematic. The two signals we`ve just generated are mixed together at the base....
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Instead of focusing on the mathematical and raw theoretical side of this simple pyro RF transmitter, we`ll be focusing on the elements in each of the stages. The math of how/why this circuit actually works is horridly ugly and way too complicated. so it`s.... -
This transmitter had its origins as a conventional shunt fed Hartley oscillator for 80 meters using a pair of 27 triodes connected in parallel; with 300 VDC on the plates of the 27`s, I was able to get about 4 watts output ( with decent stability ) for about.... -
Output transformer core: coming from flea market, light blue color, marked as A-438281-2-9H9-3, OD = 47 mm, ID = 24 mm, height = 13 mm. No information about ยต Mosfet to be used: coming from flea market, with the following characteristics. It`s an obsolete.... -
Build this circuit using a Digi-Key Electronics Barrel Crystal (CA-301), 15 Mhz for a standard output frequency of 150. 00 Mhz. If you want to customize the frequency, follow the directions below. I usually build this circuit to operate between 150 to 165.... -
This circuit operate between 150 to 165 Mhz. The Crystals I use Are The Digi-Key Electronics Barrel Crystals CA-301 Type which cost a couple of bucks per crystal. Virtually any Fundamental Crystal between 14 and 17 Mhz will output a frequency of between 140.... -
The DPT Transmitter is a dual powered Voice Transmitter that came about from quite a few request for a transmitter that would function both at power when long range was needed and with a "switch that could be thrown" for a smaller battery consumption when.... -
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The video transmissions from this unit can be received on a small Portable/Tunable and battery operated TV set such as the ones you find in flea markets, etc... -
This schematic is a tone transmitter. For sufficiently small values of the resistor, it outputs a tone, so having a resistive mic (carbon mic) in parallel with or in place of the resistor. would modulate the tone frequency with the voice. I`m not sure how.... -
Even though this CW transmitter circuit was published in 1955 in Popular Electronics, it is still legal for today`s Amateur radio operator. Portions of the 40-meter and 80-meter bands are still reserved exclusively for CW operation. As of 2011 in the.... -
Before starting on the receiver side of the` Chatterbox`, we ought to take a final look at the transmitter itself. The Chatterbox transmitter is built separately, because many constructors will want to use it in conjunction with an existing receiver on 1.....
New Circuits
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The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is.... -
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to.... -
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This.... -
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the.... -
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,.... -
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the.... -
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power.... -
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower..... -
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to....
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