The JFET-bipolar cascode circuit will provide full video output for the CRT cathode drive. Gain is about 90. The cascode configura-tioneliminates Miller capacitance problems with the 2N4091 JFET, thus allowing direct drive from the video detector..

The FM Snooper is an FM transmitter that radiates a continuous wave whose frequency is altered according to the sound waves striking the microphone. An ordinary FM broadcast receiver detects the transmitter"s output carrier. When 9-V battery, B1, is....

The various signal frequencies are obtained for an incoming carrier centered at 49.86 MHz. The receiver employs double conversion, with i-fs at 10.7 MHz and 455kHz. Ceramic filters are used in both i-fs for selectivity and reduced"coil count. A quadrature....

The circuit works from dc to 50 MHz and will deliver pulses as short as 10 ns. It is driven by a TTL signal through a 740S00 quad Schottky NAND gate, ICA through ICD. Transistor Ql, wired as a common-emitter amplifier, drives transistor Q2, a simple emitter....

The circuit has a typical voltage gain of 84 dB and a typical AGC range of 80 dB. It gives very small changes in bandpass shape, usually less than 1 dB tilt for 60 dB compression. There are no shielded sections. The detector uses a single tuned circuit (L3....

This application involves demodulation of a frequency-modulated subcarrier of the main channel. This popular example uses the PLL to recover the SCA (Subsidiary Carrier Authorization or storecast music) signal from the combined signal of many commercial FM....

The monitoring circuit consists of four tri-color LEDs driven by an equal number of op amps configured as gain-of-one inverting amplifiers. Each LED is wired in the circuit so that it glows red when the input to the op amp is high, and green when the input....

The circuit, built around an LM741 op amp configured as an inverting amplifier, is used to drive complementary transistors (Ql and Q2). The op amp`s feedback loop includes the base-emitter junctions of both transistorsan arrangement that helps to reduce....

The baby-alert transmitter is built around an LM324 quad op amp (Ul), two LMC555CM CMOS oscillator/timers (U2 and U3), and a few support components. The transmitter sends a signal on receipt of a sound at MIC1...

The circuit consists of a device with low drift LTl012. and a speed amplifier LTl022Jligh. The entire circuit is a unity gain inverter, with the summing node at the junction of three resistors 10k. The monitors what the Tl012 summing node, it compares to the....

60 kHz transformer consists of a 18 x 11mm ungapped pot core (Siemens, Fer-rocube, etc), utilizing magnetics incorporated type "F" material wound with SOV2 turns of No5 wire for the secondary and turns for the primary..

The XR-T6425 Speakerphone IC makes it possible to carry on conversation without using the handset, while the user is talking into a microphone and listening from a loudspeaker. It is ideal for hands-free conference calls. ..

This circuit uses an LED and 4081 CMOS integrated circuit. The variable resistor sets the voltage at which the LED turns on. Set the control so that the LED lights when the voltage from the car"s ignition switch drops below 13 volts..

This wideband amplifier uses only five components. External signals enter pin 3 of IC1 via ac coupling capacitor Cl. Following amplification, the boosted signals from IC1 pin 1 are coupled to the output by capacitor C2. Capacitor C3 decouples the de....

This circuit switches car headlights to the low beam state when it senses the lights of an on-coming car. The received light is very low level and highly directional, indicating the use of a lens with the detector. A relatively large amount of hysteresis is....

A normally open pushbutton switch (SI) delivers a positive input pulse to pin 4 of Ul, triggering the 1C into action. The output of Ul at pin 6 supplies base-drive current to a Darlington pair comprised of Q1 and Q2, activating . 10- capacitor and any....

The gain of the low-cost IC is internally fixed so that it is not less than 34 dB (50 times). A unique input stage allows input signals to be referenced to ground. The output is automatically self centering to one half the supply voltage. The output is also....

A low-noise LT1115 (Linear Technology, Inc.) op amp is coupled to a class-A buffer amplifier to produce a variable g..

This circuit functions as a wideband adjustable AGC amplifier. With an effective bandwidth of approximately 10 MHz, it is capable of handling rf input signal frequencies from 3.2 to 10 MHz at levels ranging from 40 mV up to 3 V pk-pk. AGC action is....

The test circuit gives an indication of the capacity remaining in a battery. By noting the time in seconds that the LED remains on after you depress the test switch Sl. The circuit has proven reliable in testing NiCad-, carbon-, and alkaline-type....

A very useful audio amp in an 8-pin DIL package. The IC features a very low minimum working supply voltage of 3V, low quiescent current, good ripple rejection, no crossover distortion and low power dissipation...

This circuit design is a class A amplifier employing both ac and de feedback. Bias is stabilized at 15 mA of the collector current using de feedback from the collector. The ac feedback, from collector to base, and in each of the partially bypassed emitter....

The low-cost Mini-Circuits MAR-X series of chips offer the RF builder a real advantage, with their inherent 50- input and output impedances (needed for RF systems). An MAR-1-based receiver/scanner preamplifier is shown. Ci and C2 are chip capacitors. Use....

This very high quality audio amp is based on the TDA1514A, a 9-pin flat package IC. The heatsink must be insulated from ground. The amplifier will deliver 40 watt into an 8ohm load with a 27.5 volt power rail or 40 watt into 4ohm load with a 21 volt power....

This amplifier operates from a 28 Vdc supply. It has a typical gain of 12 dB, and can survive operation into a 30:1 VSWR load at any phase angle with no damage. This means that with input power held constant at the level that provides 125 watts output, the....

it can reduce its gain. The time it takes for the compressor to recover from overload is determined by the rectifier The expander eg capacitor to complete the compressor is shown in FIG. 2-13B. Here is an external op amp is used for the high rate of ascent.....

Two 555s and a quad NAND-gate IC can simulate an electrocardiograph signal and a -y-wave radioisotope signal for applications in nuclear medicine. This circuit synchronizes the radioisotope signal to the EKG signal. You can use the circuit"s outputs to....

To amplify the small current signals as an electron collector inside a vacuum chamber, it is convenient for reasons of noise and bandwidth to have a "head-amplifier" attached to the chamber. Op N-amp 1 is a precision device with bipolar bias current and low....

That Circuit is a UHF TV linear amplifier for small TV transmitters with output aroun 100-200mW. The transistor BGQ136 comes with SOT-122 case has gain of 13dB at 800MHz. So with input 100mW you get 2W output and for 200mW you get 4W...

This linear amplifier delivers 10-W PEP output; with 1.25-W drive on 10 m. Tl, T2, and T3 are 10 turns of bifilar windings on an FT-50-43 toroidal core. The transformers are broadband. Filters for other bands, if desired, are shown. Note: use #26 wire for....

This circuit can generate a European police-car siren, bird noises, spaceship sounds, etc. In addition, it can be put to use as a doorbell, an alarm, etc. The circuit consists of four parts: a binary counter, a D/A converter, a VCO, and an audio output....

IC1 is a switching regulator that generates a 45-kHz signal that drives the gate of MOSFET Ql. Dl, D2, an..