"#VFO" will be shown at the bottom screen line. The steps available are 1Hz, 10Hz, 1kHz, 5kHz, 10kHz and 1MHz.Enter setup (calibration) mode by pressing ENCODER button at power-on. Push the push button 1 to change the frequency step tuning. Rotate the rotary encoder to tune up or down the frequency. To control the Si5351 I'm using Attiny85 microprocessor.Follow the schematics to wire the Arduino, Display, Si5351 module, rotary encoder, etc. As a VFO im using Si5351, it is just perfect little synthesizer for this purpose.
Audio tones from 1Hz to 20KHz have been provided.I have left for the last the VFO part of the schematic, because this is the main difference between the both variants of the receiver. Designed with a frequency setting range of 20KHz to hopefully 75MHz, but spectral performance may be poor.
There are four sets of signals that are generated inclusive of the Upper and Lower Sideband BFO Frequencies, the Main VFO (VFO A) and a Secondary independent VFO (VF The Arduino Uno DDS VFO HF signal generator project is designed as a test equipment project for home construction of test equipment used for ham radio. Here is what the three element (Nano, Si5351 and the Color TFT) brains of the Sudden Transceiver performs: Generates the Local Oscillator and Beat Frequency Oscillator signals.
It contains a Si5351 as VFO/BFO generator and also an extender, as all free digital I/O pins and Analog Inputs have been brought out on the edge of the board on the other side to make it easier to connect to main board as well as keep. All buttons are 22 connected between the pin and ground. This VFO is built on a very small pcb (5,5 x 2,5 cm) with smd components and covers dc-60 MHz.Details of the PCB with schematic are given later. This will ease the current loading by half on the Si5351 output stages. A common oscillator circuit, operating at either 25 MHz or 27 MHz, is also built in, but it needs an external crystal.Quadrature outputs - Output0 and Output1 of the Si5351a are phase shifted by 90 degrees between 3. The Si5351A consists of two synthesizers, three output dividers, one per output channel, and one output stage per channel that are all controlled via the I2C bus. Improper matching of the diode mixers can lead to a large number of spurious responses.Theory behind the Si5351A. The diode mixers need an SWR of 1:1 at all the three ports (RF, IF and the oscillator drive). The pad provides proper termination to the Si5351 and a proper drive to the diode mixers. Based on a PLL/VCXO + high resolution MultiSynth fractional divider architecture, the Si5351 can generate any frequency up to 200 MHz on each ofThe mixer is fed from clock#2 of the Si5351 through an attenuation pad. Long pressure of ENCODER button store starting VFO frequency to EEPROM and go to BFO frequency.The Si5351 is an I2C configurable clock generator that is ideally suited for replacing crystals, crystal oscillators, VCXOs, phase-locked loops (PLLs), and fanout buffers in cost-sensitive applications. ENCODER short button pressure change step (100Hz, 1kHz, 5kHz, 1MHz). Set starting VFO frequency using ENCODER rotation. Enter setup (calibration) mode by pressing ENCODER button at power-on. SSB, AM dan RF Signal Generator adalah mode yang digunakan pada VFO si5351, bisa kita select dengan menekan Switch Rotary Dial agak. Multiband Selector, 40m adalah band info yang menginformasikan panjang gelombang dari Frekwensi yang tampil pada display. YD3RDW adalah text yang dapat dipesan oleh pengguna manakala order VFO si5361. int corr = 10 // this is the correction factor for the Si5351, use calibration sketch to find value.
long freqstep = // set this to your wanted tuning rate in Hz. long iffreq = 0 // set the IF frequency in Hz. volatile unsigned long frequency = 7100000 // This will be the frequency it always starts on. si5351 vfo bfo arduino based vfo bfo q15 bss138 q14 bss138 r+ c5 1nf 2. This is fine but I wouldn't mind 10Hz increments Si5351 board Save current freq and band to EEPROM 0 mhz signal to NE602 mixers for both the transmit and receive 701MHz, padded some more to -35dBM, into the second IF ( limiter) of the SA605 701MHz, padded some more to -35dBM, into the second IF ( limiter) of the SA605.