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RF Transmitter Circuits
RF Transmitter Circuits
Valve Transmitter circuit 70W
This transmitter with a good antenna and under proper conditions of use may have a range of more than 45km. The configuration is made by the rise of the output lamp, which makes it advantageous as regards the fidelity of the emitted signal. The 6V6 lamp is used in the oscillation step. The coil L1 will be commercially available as a 6SA7...
50W Tube-Valve SW transmitter
This transmitter works in the short waves from 6MC / S to 22MC / S. Coil L1 is the short wave oscillating coil of the 6SA7 lamp and you will find it ready for trade. Capacitor C1 is variable with a capacity of 0-500pF. The coil L1 consists of 13 coils 3cm in diameter and 1mm thick wire. Capacitors C1, C2, C3 and C4 are variables with a capacity...
100W AM Valve Transmitter circuit
For our strong construction with the two 807 we do not need words. We all know the performance of such a machine. In this construction we have the peculiarity of high upward tension and independent coupling. On the output lamps, resulting in the output power being increased by several watts. We certainly will not talk about 130-150 watts, but we...
200W Valve RF Transmitter circuit
This transmitter consists of three stages. The step of the oscillator with the 6L6 lamp, the amplifier isolator with the lamp 807 and the final stage of the transmitter with the 811 lamp. The coil L1 is requested by the market as a coil of the 6SA7. The various RFCs are sold on the market and used to isolate the feed device from the generated...
300W Valve RF Transmitter circuit
It consists essentially of three stages and gives the antenna a power of 300 WATT, provided it is properly tuned. The first tier is an oscillator that has an oscillating coil L1 that will be required by the market as a 6SA7 coil. The coils L2 and L3 consist of 60 coils of 1mm cross-section wire wound on a 5cm diameter tome so that they have some...
255W Valve RF Transmitter circuit
This transmitter of 255W is depended on the coils we put at it to work in both the middle and the short waves. The power in the antenna is 255W and includes 4 states. The first consists of the EF80 that works as a COLLPITS CLAPP oscillator. Frequency selection is done in a somewhat unusual way: Instead of the variable capacitor, it uses a...
5W Valve RF Transmitter circuit
In this circuit, the wearer assembly consists of only one lamp, 6V6 or 6L6, which acts as an oscillator and as an output amplifier at the same time. Coil L1 is the medium wave oscillation coil. Of 6SA7. The coil L2 consists of 50 spools wrapped on a cylinder covered with a 3 cm diameter insulating material. The diameter of the wire is 0.5mm. The...
Mini transistor Transmitter 50mW schematic
Is this a transmitter? Medium-wave short-wave consists of three transistors. The transistor AF115, along with the rest of its circuitry, is the oscillator of the device. The circuit of the two OC72 is the low-frequency amplifier (modulator), which forms the carrier wave produced in the circuit of the AF115 lamp from its secondary transformer T1....
50W AM Valve RF Transmitter circuit
This transmitter consists of 5 in total bulbs. 6L6 works as an oscillator. Subsequently the oscillation is guided to the guide grid of 807 which acts as the ultimate amplifier and is the transmitter output lamp. The amplifier consists of the ECC83 double-stage as pre-amplifier and 6L6. The power supply feeds both the transmitter and the...
100W AM Valve RF Transmitter circuit
This transmitter, as shown in the drawing, consists of a 6V6 as an oscillator, then the signal excites an 807 which acts as a buffer. The final step consists of two 807 in Push-Pull. The amplifier consists of three in series double-triodes ECC83 and finally two 6L6 in Push-Pull. The transmitter uses two power supplies, which is why we use two...
Simple Valve MW Transmitter circuit 30W
The simplicity of this transmitter compared to its very high performance makes it very interesting. Its output power is about 30 W and its range under normal conditions, with proper antenna and handling, reaches 30 km. The oscillator is the PL 84 which provides enough signal to normally excite the output light. Coil L1 is the oscillation coil of...
27Mhz and 49Mhz rf oscillator-transmitter
The modulator and oscillator consist of two NPN transistors. The base of the modulator transistor is driven by a bidirectional current source with the voltage range for the high condition limited by a saturating PNP collector to the pin 4 Vreg voltage and low condition limited by a saturating NPN collector in series with a diode to ground. The...
This transmitter consists of a keyed crystal oscillator/driver and a high efficiency final, each with a TMOS Power FET as the active element. The total parts cost less than $20, and no special construction skills or circuit boards are required. The Pierce oscillator is unique because the high 4ss of the final amplifier power FET, 700 -1200...
This transmitter is capable of two levels of rf power. For low-power wireless video, like in a house or office, where simultaneous monitoring of program material is desirable without cumbersome hookups, 1-30 mW is available. For longer ranges up to several miles, as in amateur (ham) TV, security, and surveillance purposes, 2 W into a 50-0...
This is a little transmitter that could be put into a plastic Easter egg. It delivers approximately 1 W of measured rf output into a 50-0 dummy load, and creates no heating problems with the circuit. The crystal is a series fundamental type, and the power source provides 9 V with a 2-A supply. The transmitter can operate at another frequency,...
In a half-duplex system, information can flow in both directions, but only one direction at any given time. The conventional method of building a half-duplex link requires a separate emitter and detector, connected with directional couplers, at each end of the fiber. The GFOE1A series of infrared emitting diodes are highly efficient,...
The crystal oscillator, which uses two sections of IC1, a 4001 quad 2-input NOR gate, is a standard and reliable design. The oscillator"s 1.85-MHz, square-wave output feeds IC2, a 4017 divide-by-10 counter. The count enable and reset terminals, pins 13 and 15, are normally held high by resistor R3, and the counter is activated by bringing...
This transmitter can be used for transmitter hunts, for remote key finding, or for radio telemetry in model rockets. It can be tuned to the two meter band or other VHF bands by charging Cl and Ll. 11 is four turns of #20 enameled wire airwound, 0.25 inch in diameter (use a drill bit), 0.2 inch long, centertapped. The antenna can be 18 inches...
The unit consists of a direct conversion receiver and 1-W transmitter. The direct conversion receiver VFO is tuned just off frequency from the incoming signal. This difference in frequency produces a clean, strong, and solid audio tone signal. Detect the resonant frequency of the transmitter VFO by using the GDO as a field-strength meter....
The oscillator, Q1, is a standard overtone circuit. A fifth-overtone crystal, 80.545 MHz, is operated on the seventh overtone, 112.763 MHz. C6 couples the output of the oscillator to Q2, which operates as a doubler to 225.5 MHz. A double-tuned circuit using C7, L2, L3, C10 is used in the collector of Q2 to reduce the level of the 112-MHz...
This is a 3-W, single-circuit board, VFO-controlled CW transceiver for 40 or 30 meters, featuring a direct-conversion receiver with audio filtering, Receiver Incremental Tuning (RIT), and speaker level audio volume. The transmit frequency is generated by Ql and its associated components in tbe VFO. The buffer, Q2, isolates the oscillator from...
Hf Low-Power Cw Transmitter
Suitable for amateur use, this 1.5-W transmitter runs on a 12-V supply. Ql is an oscillator using a surplus FT2
5W 80M Cw Transceiver
This transceiver has a 3-stage transmitter and a direct-conversion receiver. Ql is the transmitter"s oscillator, an
Plate Touch Sensor Circuit
This system operates on the principle that capacitance loading of an oscillator will lower its frequency. When a foreign body comes into contact with touch plate, the frequency of Ul is lowered.
27.125Mhz Nbfm Transmitter Circuit
Using a Motorola MC2833 one-chip FM transmitter, a few support components, and an MPF6660 FET RF amp, this transmitter delivers about 3 W into a 50- load.
10M Dsb Qrp Transmitter With Vfo Circuit
The three schematics represent three building blocks for a 10-meter SSB transmitter. Or these blocks can be used separately as circuit modules for other transmitters. The VFO board uses an FET transmittal oscillator, the VFO signal is mixed in an NE602 mixer and is amplified by Q2 to a level sufficient to drive an SBL-1 mixer in the transmit...
Atv Jr Transmitter 440Mhz Circuit
This low-power video transmitter is useful for R/C applications, surveillance, or amateur radio applications. Seven transistors are used in a crystal oscillator-multiplier RF power amplifier chain, and a high-level video modulator. A 9- to 14-Vdc supply is required.
Simple Fm Transmitter Circuit
Running from a 9-V battery, this transmitter can be used as a wireless microphone with an ordinary 88- to 108-MHz FM broadcast receiver. Keep the antenna length under 12 inches to comply with FCC limits. LI is 6 turns of #24 wire wound around a pencil or a 14 form, with turns spaced 1 wire diameter.
Vacuum Tube 80-40M Transmitter Circuit
Using a 6BW6 vacuum tube, the above transmitter delivers about 5 W output. CI is adjusted for cleanest CW note. C8 and C9 are 365 pF and dual-365 pF (paralleled) tuning capacitors. LI is 35 turns of #24 enamelled wire on a 1 plastic tube. FT-243 crystals for 3.5 or 7 MHz are used.
49Mhz Fm Transmitter Circuit
This 49-MHz FM transmitter consists of an audio amplifier, a low-pass filter, three RF stages, and a regulated-dc power supply. The output is about 16 mW into a 50- load. This transmitter can be used in many 49-MHz applications, such as in a baby monitor, cordless telephone,
1750M Transverter Circuit
This circuit was described in a recent edition of an amateur radio magazine. It allows operation in the 160- to 190-kHz band with up to 1 W (license free) in any mode (CW/SSB/FM, etc.) It consists of a receiving converter for 5 kHz to 450 kHz and a transmitting converter to convert the 3.66- to 3.69-MHz (80 meter) range to 160 to 190 kHz.
10M Dsb Transmitter Circuit
A DSB transmitter is much cheaper to build than an SSB transmitter because no filter or phasing networks are required. This circuit produces up to 1-W output on the 10-meter band. The frequency 28.322 MHz is used, which is a commonly available clock frequency crystal. CW operation is also provided.
FM Radio Circuits
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Ultrasonic distance finder circuit
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 measured. There are three main categories of distance measurement methods in use: a) By...
Simple Metal detector circuit with CD4030
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 find something potentially valuable, hidden a few centimeters below the soil. So many...
Fully automatic watering circuit for flower pots
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 circuit comes as a solution to this problem. Depending on humidity of the pot at...
Simple deep searching metal detector circuit
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 circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
Sub-Harmonic Bass Converter for Electric Guitars
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, such as filtering or distortion. Instead, a frequency division system produces outputs...
Echo Depth Sounding Sonar for Boats
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 calibration of the rope. This arrangement still exists in some yachts. The big...
100W HiFi Audio Amplifier Circuit
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 supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
Plant-Pot Water Level Indicator Circuit
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 circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
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 have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
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