All posts in the 'Signal generator' Category
The QRP2000 is a transceiver based on the KK7B R2 single signal direct conversion receiver and it’s companion T2 phasing exciter. Using these two modules together with band pass filter, PA and LPF modules from Hands Electronics aim to produce a CW/SSB transceiver covering all amateur bands from 1.8-30 Mhz.Modes available are USB/LSB and CW.[more]
The aim was to produce a DDS controller with minimum hardware, that would offer a good linear tuning rate at 10Hz steps.The project uses an AD 9850BRS from analog devices, an industry standard two line LCD display, two PIC16F84ย�processors to manage the DDS and display, an optical shaft encoder and a pair of MMIC amplifiers to generate up to +10dBm to drive a diode ring mixer.[more]
Here’s a wonderfully-simple project first done by Curtis Preuss, WB2V in the July ‘97 issue of QEX. The article was entitled “Building a Direct Digital Synthesis VFO” and was geared as a straightforward starting point for building and evaluating a DDS VFO based on the Analog Devices AD9850 chip.Curtis used the PIC1654 microcontroller but this project ported the PIC16C54 software to work on the PIC16C84 .[more]
This circuit is a oscillator where the frequency can be programmed from 0 to 25 MHz with the resolution of 0.01Hz.The purpose of this project is to learn about DDS circuit.The AD9835 combines the Numerical Controlled Oscillator (NCO), COS Look-Up Table, Frequency and Phase Modulators, and a Digital-to-Analog Converter on a single integrated circuit.[more]
This project is dedicated for AVR nerds who can not touch anything else but AVR chips.This board is functional copy of JUMA-TX1 DDS board done with Atmel Atmega88 microcontroller. Because of higher pincount serial(RS232) interface have been added to the board for PC communication. Surface mount version (MLF package) of Atmega88 chip is used. 6-pin Atmel ISP programming connector is added for in circuit programming. [more]
