Miniature Transmitter For Small Bird

IntroductionThe goal of this project was to build a small, cheap, light-weight telemetry transmitter to attach to a small bird.Specifically:* Telemetry Tranmission should be tuned to the 2-meter band.* Battery life in the field should exceed 3 months without replacement.* Range should be 500 meters.* Weight less than 10 grams.The CircuitThis...

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Miniature Telemetry Transmitter

Telemetry or "remote measurement" is a highly automated communications process by which measurements are made and other data collected at remote, inaccessible or dangerous places, and then relayed by a telemetry transmitter to receiving stations for display, monitoring, and recording. The original telemetry systems were termed "supervisory" because they were used to monitor electric power distribution. Communication channels form...

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RF Filter Types

An RF filter is an electrical circuit configuration (network) designed to have specific characteristics with respect to the transmission or attenuation of various frequencies that may be applied to it. There are three general types of RF filters:A high pass filter similarly has a cut-off frequency, above which there is little or no loss in...

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RF Power Amplifier Design Formula

An RF power amplifier is a type of electronic amplifier used to convert a low-power radio-frequency signal into a larger signal of significant power, typically for driving the antenna of a transmitter. It is usually optimized to have high efficiency, high P1dB compression, good return loss on the input and output, good gain, and good heat...

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Audio Video Wireless Transmitter

In this fast-paced world, there is little time for inconveniences and a greater need for portability and adaptability. The idea for an Audio/Video transmitter stems from this need. There may have been times when you've wanted to hook up your VCR from one room to another television set in another room.But that would have entailed that you...

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FM Transmitter With LCD

This fm project is fm transmitter using phase locked loop (PLL) method. PLL controlled by PIC16F84A or 16F628A and I2C IC TSA5511 from Philips with LCD display. The fm transmitter is very stable on working frequency 88-108 MHz.Oscillator of the fm transmitter is generated by a FET transistor BF981 and varicap BB809 and buffered by BFR91,...

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More 1934 Transmitter

After collecting all of the parts comes "playing checkers" to find the best layout given the set of parts located. In this case I found suitable 30's parts for all of the major components except the chassis itself. For it I'm using a 17"x10" sheet of 18 gauge aluminum. It will be fastened to a 4 1/2" tall wooden frame and then frame and aluminum...

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A 1934 Style Transmitter

Since the AWA Linc Cundall OT CW Contest in January I've been thinking about building another transmitter, this one falling in between my 1929 TNT transmitter and my Thordarson 100 or late 30's 6L6 transmitters. I want to use it with my National FB-7 so it needs to be an early to mid 30's design.A popular design in the early 30's used a type...

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AM FM Radio Spectrum and Frequency

Radio SpectrumFM radio works the same way that AM radio works. The difference is in how the carrier wave is modulated, or altered. With AM radio, the amplitude, or overall strength, of the signal is varied to incorporate the sound information. With FM, the frequency (the number of times each second that the current changes direction) of the...

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What is Transmitter Hunting?

Transmitter Hunting (known as T-Hunting, Fox Hunting, Radio Direction Finding) is a popular activity among Amateur Radio operators where a transmitter is actually hidden somewhere and "hunted down" (found) using radio direction finding techniques!The transmitter is usually on the air intermittently, and identifies either in Morse code or voice automatically.Amateurs participating in transmitter hunts usually start at a common...

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What is Transmitter?

What is transmitter?A transmitter is an electronic device which propagates an electromagnetic signal such as radio, television, or other telecommunications. It is usually with the aid of antenna.Transmitter TypesIn radio electronics and broadcasting, a transmitter usually has a power supply, an oscillator, a modulator, and amplifiers for audio frequency (AF) and radio frequency (RF). The modulator is the device which piggybacks...

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70-210 MHz RF Oscillator Circuit

The RF Oscillator is based on a Hartley oscillator. The frequency is determined by L1 and capacitor C1. The Vtuning voltage will change the capacitance in the varactor BB132 wich will change the oscillation-frequency. The value of capacitor C2 will determine how much the frequency can be changed by the tuning voltage. The larger value the...

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1W FM Amplifier For Ipod FM Stereo Transmitter

The schematic show you a RF amplifier with very high gain. The feeding RF signal enter C9 to transistor Q1 which has a self biased working point. The gain and working point is set with the two resistors R1 and R2. FB1, C5, C6 works as filter for rejecting RF to power line. Q1 has a gain about 15dBm. The output signal can be found a the collector...

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