Circuits & Schematics Radio - 4

Miguel A. Vallejo The software The software is written in C using avк-gcc under Windows (WinAVR). LCD routines are based on Fandi Gunawan's Nokia 3310 routines and CYWM6935 routines are based on the code of Jason Hecker (see at the bottom for ...

Miguel A. Vallejo After visiting some web pages about 2.4 GHz ISM band spectrum analyzers based on the CYWM6935 module, I tried to build my own analyzer, but with some improvements. The references I found on the net used the parallel port or a ...

Here is a simple transmitter that when connected to a phone line, will transmit anything on that line (execpt the dial tone) to any FM radio. The frequency can be tuned from 88 to about 94Mhz and the range is about 200 feet. It is extremely easy to ...

Andy Collinson Description 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 The ZN414 ic has now been replaced by the MK484 which is identical in performance and pinout. Click to enlarge Notes: Designed around the popular ZN414 IC this ...

Izhar Fareed This FM transmitter (FM Tx) is about the simplest and most basic FM Tx it is possible to build and have a useful transmitting range. It is surprisingly powerful despite its small component count and 3V operating voltage. It will easily ...

This project will explain how I build my new wattmeter. This watt meter will be able to measure power from 300 nW to 30 W @ (0-500 MHz). This wattmeter is based up on a dummy load of 50 ohm which can handle 50 W. The measurement will be displayed ...

1x BH1417 - Stereo PLL Transmitter IC (Case SOP22) 1x 7.68 MHz Crystal 1x MPSA13 - NPN Darlington Transistor 1x 2.5 Turns Variable Coil 1x MV2109 - Varicap Diode 1x 4-DIP Switch ANT - 30 cm of copper wire 1x 22K Resistor 7x 10K Resistor 1x 5.1K ...

Mike Perez Over the past few months I've been contemplating a few projects for some WRTSL54GS routers with OpenWrt,however I really need these to have a high gain antenna on the WRTSL54GS. As you may recall, this model has a fixed antenna, with ...

Introduction This circuit stores a single morse code message as bits in an EPROM chip, the message is sent to a relay which can key a CW transmitter. The keyer can output either a one-shot message such as CQ DX DE CALLSIGN, or a continuous message. ...

Alan Yates Michael Rainey (AA1TJ) has been acting as my muse again. He knows of my fondness for minimal component radios and sent me an old Italian article Il Pigmeo, which features a one-transistor 27 MHz walkie talkie (apparently capable for 400 ...