Radio Clock for PC`s
The three best known of these signals are the DCF77 signal broadcast from Mainflingen near Frankfurt in Germany on 77.5kHz which can be received through out mos...
AM-Receiver for Aircraft comm (118.250MHz)
The aircraft communication in Sweden is still Amplitud Modulated (AM). The local airport (Axamo) use the frequency 118.250 MHz. The reveiver I will explain is a...
AM-Receiver for Aircraft comm (118.250MHz)
The aircraft communication in Sweden is still Amplitud Modulated (AM). The local airport (Axamo) use the frequency 118.250 MHz. The reveiver I will explain is a...
AM/FM/SW active antenna
This circuit shows an active antenna that can be used for AM, FM, and shortwave (SW). On the shortwave band this active antenna is comparable to a 20 to 30 foot...
AM/FM/SW active antenna
This circuit shows an active antenna that can be used for AM, FM, and shortwave (SW). On the shortwave band this active antenna is comparable to a 20 to 30 foot...
AM Receiver
This is a compact three transistor, regenerative receiver with fixed feedback. It is similar in principle to the ZN414 radio IC which is now replaced by the MK4...
AM Receiver
This is a compact three transistor, regenerative receiver with fixed feedback. It is similar in principle to the ZN414 radio IC which is now replaced by the MK4...
Medium Wave Active Antenna
This circuit is designed to amplify the input from a telescopic whip antenna. The preamplifier is designed to cover the medium waveband from about 550Khz to 165...
Medium Wave Active Antenna
This circuit is designed to amplify the input from a telescopic whip antenna. The preamplifier is designed to cover the medium waveband from about 550Khz to 165...
RF Actuated Keying Monitor
Sending Morse on a rig without a sidetone is not impossible, but is not particularly pleasant either. This battery-powered monitor has been designed to provide...
RF Actuated Keying Monitor
Sending Morse on a rig without a sidetone is not impossible, but is not particularly pleasant either. This battery-powered monitor has been designed to provide...
Simple RF Power Meter
Many beginners trying out their skill with QRP TX, for the first time have to overcome many problems before they are able to come on the air. On usual complaint...
Simple RF Power Meter
Many beginners trying out their skill with QRP TX, for the first time have to overcome many problems before they are able to come on the air. On usual complaint...
Radio Spectrum Monitor
This is an experimental work to monitor a spectrum pattern of radio band, and is a continuous project from Audio Spectrum Monitor. To analyze the spectrum of an...
Radio Spectrum Monitor
This is an experimental work to monitor a spectrum pattern of radio band, and is a continuous project from Audio Spectrum Monitor. To analyze the spectrum of an...
Field Strength Meter
This is a wide band signal strength meter circuit which responds to small changes in RF energy, designed to be used for the VHF spectrum and will respond to AM ...
Field Strength Meter
This is a wide band signal strength meter circuit which responds to small changes in RF energy, designed to be used for the VHF spectrum and will respond to AM ...
Simple Field Strength Meter
This Field Strength Meter is simple and also quite sensitive. It uses an ordinary digital voltmeter to measure RF signal strength up to a few hundred MHz. The m...
Simple Field Strength Meter
This Field Strength Meter is simple and also quite sensitive. It uses an ordinary digital voltmeter to measure RF signal strength up to a few hundred MHz. The m...
UHF Preamplifier
This circuit is designed to work at UHF frequencies in the range 450-800MHz. It has a gain of around 10dB and is suitable for boosting weak TV signals. The circ...