Mini OCXO (Oven Controlled Crystal Oscillator) generator with independently programmable 3x outputs, 330 kHz to 330 MHz (1 Hz step), plus a direct 10 MHz output

>> Assembled units: check the PCS Electronics shop! <<

Areas of potential use:

• Stable reference frequency for radio communications: transmitters, receivers
• Amateur radio: QO-100, VHF, SHF, FT8
• Laboratory-grade, stable RF signal source
• High end audio for synchronizing Hi-Fi ADCs and DACs
• Analog and digital radio and TV broadcasting
• Laboratory work, with three independent channels precisely in phase and thermally stabilized

Default frequencies are 40 MHz for output 1, 25 MHz for output 2, 24 MHz for output 3.

To change output frequencies:

• Connect the OCXO to your computer by using a standard “type C” USB cable;
• Run a serial terminal software, such as PuTTY or HyperTerminal, and open a virtual serial port (baudrate and other settings do not matter);
• Type “?” (without quotes) and press Enter for a help;
• Enter “fq 1 30000000” to set the frequency of output 1 to the value of 30 MHz;
• Change other output’s frequencies, if needed, and then enter “load” to update the outputs;
• The frequency settings will be stored in a non-volatile memory.

There are two user profiles; use the "Set" button to switch between the profiles.

Fine-tune the frequency (plus-minus about 1ppm) with a "-+" trimmer.

Modify/compile the code yourself: set up the Arduino environment

Install the board as described here: https://github.com/DeqingSun/ch55xduino

( See also: https://sourceforge.net/p/sdcc/bugs/3569/ )

Tools - Board - CH5xx boards - CH552

Tools - USB settings - Default CDC

Tools - Upload method - USB

Tools - Clock source - 24 MHz internal

Updating the firmware:

Install and run the WCHISPTool from http://www.wch-ic.com/downloads/WCHISPTool_Setup_exe.html

Tab: CH55x Series

Chip model: CH552, download type: USB

User file: select the HEX file with a firmware.

Connect the PROG jumper, cycle the power (not the USB port!), remove the PROG jumper

Check the Device Manager: under "Interface" branch, there should be a "USB module" device.

If there is an "Unknown device", go to the WCHISPTool folder and install the driver.

In the WCHISPTool, click Search and make sure the "MCU model: CH552" appeared in the list.

Click Download

Cycle the power

Now the Device manager will list a new "USB Serial Port" under "Ports (COM & LPT").

Alternatively, instead of WCHISPTool, use vnproch55x :

vnproch55x firmware.hex -r2