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Revision as of 15:46, 7 October 2021 by Ok1zia (talk | contribs) (Windows)
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Davac 4.0 OK1ZIA

Davac 4 was succesfully built by OK1USW, OK1UGE and OK2JTB.

Circuit diagram

Circuit diagram of Davac 4.0


Note: 600 DPI have images in Full resolution, MediaWiki uses thumbnails.

PCB www.hamshop.cz


Ondra OK1CDJ has made PCBs and offers it at www.hamshop.cz. Many TNX!


  • Jack holes are slightly smaller - user Dremmel milling cutter
  • Parts values would be shown - use schematic


Transformer TR-1/1 www.tme.eu

Jack 6.35 K3606D www.gme.cz or K36092B

White connectors for cable pins

Black connectors for cable flat cable

Program the FT232R

As default, the FT232R acts as serial port. But Tucnak uses Libftdi to access it in bitbang mode. Default VID:PID must be changed to distinguish Davac from other USB serial ports.


I'm pretty sure you can use ft232r_prog. But I have no experiences with it. If you try it, please let me (OK1ZIA) know, I will update this information.


MProg with loaded Davac4.ept

Under Windows, use MProg. Download File:Davac4.ept and open it in MProg. Note on Windows XP you need D2XX drivers; on newer versions they are installed automatically.

Unplug all other FTDI devices and press the Program All Existing Devices button.

Install USB drivers


You have nothing to do, It will work automatically. Only on specific distributions you may have to set permissions to USB device, which is normally done by udev script.


Zadig with Davac4

Under Windows 7 or newer, use Zadig. On XP use 2.2.

Click Options, List All Devices.

Keep libusbK and press Install Driver.

SMT variant by OK2JTB

All data: File:Davac4-ok2jtb.zip

If you want this PCB, try to ask OK1WMR.

Made by OK1UDC(SK) & OK1UGE

Note OK1ZIA: better use USB-B type connector

Combined Davac4 and contest machine RPi

Guys from OK1RPL made this amazing compact contest solution.