Radar Calibrator Circuit
This circuit is basically a system that generates a pulsed modulation signal for a Gunn diode microwave oscillator. Several speed settings are preset (S3 a and...
Pattern Generator For Radio Direction Finding Circuit
In order to display polar quantities (magnitude and direction of a received radio signal), a sine and cosine voltage proportional to an angle (antenna directio...
Receiver-Interface Circuit For Preamps Circuit
The purpose of the receiver/interface circuit is to pass RF to the receiver through capacitor 09,...
Relay Interface For Amateur Radio Transceivers Circuit
The relay power in the linear is obtained from the -120-V bias supply, and the transmit keying output from the Kenwood is +12 V at 10 mA maximum. The key ingre...
455-Khz Narrow-Band If Filter Circuit
This filter uses five 455-kHz ceramic resonators. The impedance is 330, the bandwidth is 800 Hz, and the ultimate rejection >60 dB....
Simple Field Strength Meter Ii Circuit
This simple field-strength meter provides a cheap way to monitor an amateur radio or CD transmitter (or even an antenna system)...
Simple Field Strength Meter I Circuit
Useful for checking transmitters and antennas, this circuit uses a voltage-doubling detector D1 and D2 (HP 5082-2800 hot carrier types). D1 and D2 can also be ...
Simple Amplified Field Strength Meter Circuit
This circuit uses a FET as a dc amplifier in a bridge circuit. R4 is set for meter null with J1 short circuited. Any surplus 50-mA meter can serve in this circ...
Remote Field Strength Meter Circuit
This field strength meter consists of a tuned crystal detector producing a dc output voltage from a transmitted signal. The dc voltage is used to shift the fre...
455Khz Fm Demodulator Circuit
Useful for NBFM reception on older shortwave receivers lacking tills capability, This circuit uses a PLL IC, an N565N, to achieve this. It was originally used ...
Simple Full-Wave Envelope Detector Circuit
Simple, yet sensitive, this amplifying full-wave detector circuit has an almost zero rectification threshold. It presents a highly linear RF load to the final ...
Fm Demodulator Circuit
An LM311 comparator converts a small analog signal to a digital level for the DC4046 phase-locked loop, which is configured as a first-order FM demodulator. Th...
Atv Downconverter Circuit
This RF converter converts amateur TV signals in the 420- to 450-MHz region to VHF channel 3 or 4, allowing reception of those signals on a standard TV receive...
439.25Mhz Atv Downconverter Circuit
Most ATV (Amateur Television) transmitters transmit a DSB signal and commercial television stations use a VSB (Vestigial Sideband) signal. This fact is made us...
Simple 2M 6M Transverter Circuit
Using the bilateral properties of a balanced mixer this transvertcr will produce 6-m output with 2-m inputs. Y1 is a 90-MHz crystal. Note that the input on 2 m...
Crystal Controlled Frequency Converter Circuit
The second gate (G2) of a MOSFET can be used to incorporate a crystal oscillator into the same stage as a frequency mixer. Although old hat with tubes, this sc...
800 To 1000Mhz Scanner Converter Circuit
This converter enables reception of 800 to 1000 MHz on any scanner covering the 400 to 500-MHz range. The converter can be set up to cover either 800 to 900 MH...
Simple Wwv Converter For Auto Radios Circuit
This simple frequency converter mixes the 15-MHz WWV/WVH signal with a 16-MHz signal from the LO to convert it down to 1 MHz so that it can be heard...
High-Performance Shortwave Converter Circuit
The NE602 chip, Ul, contains oscillator and mixer stages. The mixer combines the oscillator signal with the input RF signal to produce signals whose frequencie...
Loop Antenna Preamplifier Circuit
This preamplifier has a built-in regeneration control boost gain selectivity. CI is a single or multi-gang AM broadcast-band tuning capacitor. LI is a ferrite ...