25-200 MHz Wireless Frequency counter

This frequency counter has 6 digits and will work from 25MHz up to 200MHz that you don't need to connect it with any wires to your equipment. Wires-interference and drift in the oscillation frequency. This counter use a small pick up coil to probe the oscillation. Just hold the pickup coil a few cm from the main oscillator coil and read the...

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Stereo Compressor Limiter with Clipper for FM Broadcast

This application circuit is stereo audio compressor limiter with clipper for processing your FM audio signal. Limiter is a device, which weakens loud signals and intensifies silent signals. On its output there is signal with constant level. Signal clipping on the limiter output allows to increase the signal level without exceeding maximum...

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C-Quam AM Stereo Decoder MC13028

This electronic circuit is AM stereo decoder that accepts the signal from the IF of a receiver (450 or 455 KHz) and decodes stereo medium wave broadcasts. It operates at 8-15VDC and provides standard level left and right audio output for direct connection to the audio amplifier.It may be used to support 30Hz-15KHz audio but it depends on...

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5 MHz Bandwith Video Signal Amplifier

This video signal amplifier circuit is a broad band amplifier which will take the video signals from your VCR and will amplify them sufficiently to drive up to 3 monitors, TV sets (provided that they can accept direct video signals), or other VCR’s for recording from one video to up to three others. It will also make possible to record from...

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50W Linear FM Amplifier with BLY90

This RF FM Amplifier is always essential for the amateur that wants it strengthens some small transmitter. The present circuit of BLY90 can give 50-60W power out with input control 15-20W in FM band II 88-108 MHz. FM amplifier schematic CircuitPrinted Circuit BoardFM Amplifier Parts ListC1-C4 = 10-80pF C5 = 10nF C6 = 1000pF C7 =...

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4 Watt PLL FM Transmitter

This transmitter circuit uses PLL method to generate stable frequency and the output power is selectable from 1 to 4 watts via an on-board jumper switch. It's designed using wide-band power amplifier technology, this eliminates the need to tune up the transmitter to "peak the power".This PLL FM transmitter has an "Out Of Lock Power Down"...

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4 Watt PLL FM Transmitter

Here's a Phase Locked Loop (PLL) FM transmitter circuit with high gain amplifier on the final stage. If the unit is to be used with a stereo encoder, the pre-emphasis must be disabled. The audio input network has a potentiometer to set the audio level and jumper selectable pre-emphasis.The PLL FM transmitter uses the standard PLL architecture....

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FM Stereo Encoder NJM2035

This stereo encoder is the perfect solution for those looking for a high quality stereo sound transmission at a low cost. This stereo encoder produces an excellent crystal clear stereo sound and very good channel separation that can match with many more expensive stereo encoders that are available on the market. It is all possible thanks...

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FM Stereo Encoder BA1404

This FM stereo encoder uses IC BA1404 for transmiting on FM band broadcast. Sub carrier frequency generated from 38 KHz Crystal. FM Power output is around 250mW. For input preamplifier used a couple of IC 741. You need a fm amplifier for boosting rf signal.Stereo Encoder Schematic circuitBA1404 datasheetAnother Stereo Encoder CircuitYou may...

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More 1934 Transmitter

I've gotten the components all mounted and the transmitter is ready for wiring. I learned a few things along the way...30s vintage Sangamo mica capacitors are large enough that they don't mount well on their own leads. Each one must be mechanically supported, either by a solder strip or by screwing to the wooden sides of the chassis.The wooden...

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Synthesised WideBand FM Transmitter

This project is a complete crystal-controlled Wide Band Frequency Modulated (WBFM) transmitter delivering a power output in the order of 10 milli-watts (+10dBm) using simple components. The transmitter is based upon the Phase-Locked Loop (PLL) principle, but due to the circuit's simplicity a true "phase lock" can never be achieved.The transmitter...

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250mW FM Power Amplifier

This project is a simple 2-transistor VHF power amplifier, with about 16dB gain, and requires no tuning or alignment procedures. Wideband techniques have been used in the design and the circuit is equipped with a "lowpass" filter to ensure good output spectral purity. The project has been designed for assembly on a single-sided printed circuit...

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1W AM Transmitter

This AM transmitter circuit provides a nice, clean output of about 1 Watt (carrier power). Though designed for the medium wave band (circa 1.5 MHz) it would work equally well on higher frequencies (6.2 MHz for example) with a few tweaks in component values (see table on left - C15 should be adjusted for maximum output).The carrier (produced...

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2.5 W FM Power Amplifier

This rf power amplifier design for a 2.5 Watt power amplifier for the FM band. An input of 50 mW gives a final output power of 2.5 Watts with a 13 Volt supply. The best bit is that the amplifier requires no tuning once it's built - it gives roughly the same gain and output power right across the FM band from 88 to 108 MHz.There's even some...

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88-108 MHz PLL FM Synthesizer

This fm synthesizer circuit is played with and optimised design for an 88-108 MHz synthesiser, programmable in 25 kHz steps. It produces about 50 mW output (and thus feeds nicely into the amplifier shown below) with no tuning required other than to set the inputs of the divide-by-N counter to the wanted frequency.FM modulation is achieved...

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Audio Processor for AM Transmitter

This audio circuit is used for AM transmitter audio procesing. It equipped with low pass filter circuit for AM spectrum. It's easy for use.MK1 AM Audio ProcessorMy first attempt at an improved audio processor for GCR using a Plessey SL-6270 VOGAD (VOice controlled Gain Adjusting Device) which is designed more for PMR use than broadcast use...

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FM Stereo Encoder

This Stereo encoder circuit built with MC1496. It produces a very clean signal with good separation (it performed as well as any other encoder, which included some expensive professional ones) and has been used on many professional commercial radio stations. There's no input filtering on it so it has to be proceeded by a 15 kHz low-pass...

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QRP from Frontenac State Park

Sunday afternoon, July 5, I got over to Frontenac State Park for some picnic table QRP. The picnic area there sits at the edge of a 400' bluff over looking the Mississippi River. Below the park is Lake Pepin , a naturally wide part of the upper Mississippi. To the east, across the Mississippi/Lake Pepin, is Wisconsin. The weather Sunday...

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My version of the BakerTweet

In case you haven't heard about the awesomeness, the BakerTweet (www.bakertweet.com) is an Arduino based twitter client. It's a little box that sits on the wall of a bakery, and whenever something tasty comes out of the oven, the baker can select the product and let the world know via Twitter that there's a fresh batch of croissants ready.I thought this was a great idea! And I've been wanting an excuse to hook my Arduino up to...

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Cheap Joystick and Accelerometer for Arduino from Wii Nunchuck

For ages now I've been wanting to play with an accelerometer but didn't really fancy paying £20-25 for the privilege. I'd also seen a lot of posts about people using the joystick from a Wii Nunchuck to control robots, servos, cameras, etc, which I didn't have a lot of interest in. Then I remembered that the Nunchuck controller actually has...

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Stereo FM Transmitter BH1415F

This Electronic circuit is a stereo FM Transmitter based on BH1415F wireless audio link IC. Phase Locked Loop (PLL) controller use PIC16F628 and the the PLL frequency programming can be displayed with 8x2 and 16x2 LCD. Frequency Range 88-108 MHzBH1415F can be supplied with 6 - 15V voltage, consumes only around 25mA while providing very sound...

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