AM portable radio receiver by ZN414 IC

An AM portable radio receiver made from the ZN414 IC. The ZN414 ic has now been replaced by the MK484 which is identical in performance and pinout.

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Micro Power AM Broadcast Transmitter

In this circuit, a 74HC14 hex Schmitt trigger inverter is used as a square wave oscillator to drive a small signal transistor in a class C amplifier configuration. The oscillator frequency can be either fixed by a crystal or made adjustable (VFO) with a capacitor/resistor combination. A 100pF capacitor is used in place of the crystal for VFO operation. Amplitude modulation is accomplished with a second transistor that controls the DC voltage to the output stage.


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Antenna tuning pdf file

Antenna tuning pdf file

Source : http://www.educypedia.be/electronics/antennawifi.htm

Antennas & Transmission Lines

Antennas & Transmission Lines omnidirectional antenna, biquad antenna, cantenne, horn antenna, Yagi Antenna, pdf file

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Antennas for 2.4 GHz WiFi

Antennas for 2.4 GHz WiFi wide angle antenna for 2.4 GHz WiFi, sector antenna for 2.4 GHz WiFi, Modified 3D Corner Reflector Feed for SAT TV offset parabolic dish, 2 el. BiQuad Feed for Offset Dish at 2.4 GHz WiFi, ...

Link : Antennas for 2.4 GHz WiFi

Antennetechniek voor WISPs

Antennetechniek voor WISPs biquad, cantenne, Biloop antenne

Source : http://www.educypedia.be/electronics/antennawifi.htm

Antenna construction

Antenna construction Quarter wave omnidirectional antenna for 2.4 GHz, omnidirectional antenna, Omnidirectional collinear antenna for 2.4 GHz, Biquad antenna for 2.4 GHz, Biquad antenna as a 2.4 GHz feeder for a Parabolic Dish, Can antenna for 2.4 GHz, pdf file

Source : http://www.educypedia.be/electronics/antennawifi.htm

Antenna Basics

Antenna Basics 1/4 Wavelength Ground Plane, Yagi antenna, horn antenna, Parabolic Dish, focus f = D²/16.c ; D= diameter of the parabola, c is depth of the parabola, BiQuad antenna, pdf file

Source : http://www.educypedia.be/electronics/antennawifi.htm

802.11 Wireless LAN Cards

802.11 Wireless LAN Cards schematics

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2.4 GHz WLAN Radio Interface

2.4 GHz WLAN Radio Interface IEEE 802.11b radio interface, Radio signal propagation at 2.4 GHz, Link budget calculations, pdf file

Source : http://www.educypedia.be/electronics/antennawifi.htm

2.45 GHz power amplifier with the BFG480W

2.45 GHz power amplifier with the BFG480W At a frequency of 2.45 GHz, a supply voltage of 3.0 V, and a control voltage of 3.0 V, the amplifier delivers an output power of 19 dBm at an input power of 8 dBm, with a power added efficiency of 38 %, pdf file

Source : http://www.educypedia.be/electronics/antennawifi.htm

2.4 GHz low noise amplifier with the BFG480W

2.4 GHz low noise amplifier with the BFG480W This application note gives an example of a 2.4 GHz LNA with the BFG480W. Because this LNA design has a high third order intercept value of 17 dBm (measured at input), it can be used for Wireless Local Area Network (WLAN) front-end and Wireless Local Loop (WLL) applications, pdf file

Soruce : http://www.educypedia.be/electronics/antennawifi.htm

2.4GHz AntennaAlignement

2.4GHz AntennaAlignement This paper attempts to provide some insight into the nature of radio propagation in that part of the spectrum (upper VHF to microwave) used by experimenters for high-speed digital transmission. It begins with the basics of free space path loss calculations, and then considers the effects of refraction, diffraction and reflections on the path loss of Line of Sight (LOS) links

Source : http://www.educypedia.be/electronics/antennawifi.htm

How to buy Motorola Talkabout T9500 2-Way Radio

The Motorola® I9550 Camo 25 Mile two-way radio is ready for your long distance communication needs. The unit is iVOX enabled for easy to use, hands-free communication without the need for an audio accessory. The NOAA Weather Alert Radio provides you...

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Morse Code Practice Oscillator

This simple code practice oscillator project for beginners to Continuous Wave Morse Code uses a 555 timer to generate a dit or dah sound when the key is pressed.

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More circuit by IC 555
More about Oscillator Generator
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Read link : http://www.electronics-project-design.com/CodePracticeOscillator.html

Ham Radio Circuit - Morse Code Filter Project

This project will help to filter out the interference signal and ensure that the signal received from the Morse code station stand out.

Read more : http://www.electronics-project-design.com/HamRadioCircuit.html

Active FM Antenna Amplifier (link)

2SC2570 Active FM Antenna Amplifier (link)

Alternating On-Off Switch, #2(link)

Alternating On-Off Switch, #2(link)
This circuit is the transistor version of the 4069 cmos type. Every press of the push-button will activate or de-activate the relay.

VHF-HF TRANSVERTER

This little circuit is a transmitting and receiving converter (transverter) that converts a FT290 or similar multimode handheld transciever to the 14MHz amateur band. The project is a single board module that needs an external local oscillator, for example, the VHF harmonic oscillator (or QRP VHF FM TX) LO for transverter project. It should be a relatively simple matter of scaling coils and caps to convert other bands. You may choose to omit the TX/RX switching and the TX mixer and use this unit as a receive converter giving 14MHz - 16MHz coverage on a multimode VHF receiver.

If you choose to use the full transverter circuit then you will be pleasantly surprised at the spectral purity of the transmitted signals. All unwanted spurious signals and even oscillator breakthrough are well under -75dB at the output terminal. The HF TX output from the unit is about 2mW and will give a full ten watts from my 10-Watt HF linear amplifier. The VHF rig must be of the type that also delivers +10v DC at the antenna socket on transmit. This is true of the FT290, C58 and most multimode handportables.

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http://web.telia.com/~u85920178/conv/conv-00.htm

Active Antenna for AM-FM-SW

Active Antenna for AM/FM/SW:
This simple little circuit can be used for AM, FM, and Shortwave(SW). On the shortwave band this active antenna is comparable to a 20 to 30 foot wire antenna. It is further more designed to be used on receivers that use untuned wire antennas, such as inexpensive units and car radios.

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