Receivers
Mobile phone sniffer - gsm telephone detector
With this mobile phone sniffer will track down mobile phones. Use this handy directional finder in situations and locations where the use of a mobile phone is forbidden. This neat unit will not only detect the presence of mobile phone activity (voice or text), it can home in on the culprit!
Apart from mobile phones this [...]
Preselector for SW receivers
The entry low capacitance of MOSFET modern, with two gates, will create negative inverse reaction through a uncoupled source resistor. Applied right this technique allows the creation of a entrance RF stage field with a relatively high dynamic range.
Radio amateur working on short wave: there is no need to tell, in the days of our [...]
Squelch schematic
Squelch is a circuit that acts to suppress the audio (or video) output of a receiver in the absence of a sufficiently strong desired input signal. This squelch circuit is simple and has an amplification for sufficiently large to be incorporated into an assembly of automatically control from a wide range of radio receivers. [...]
