Davac5
Davac 5 is new design of voice/SSB keyer for Tucnak. Although version 5 may appear to be a successor to version 4, is not true. It brings some advantages but also lacks some features.
To choose the version that best suits your requirements, please look at the table:
| Davac 5 | Davac 4 | |
|---|---|---|
| Size | small | bigger |
| Drivers required | No | Yes |
| Isolated | No, use the USB isolator | Yes |
| Band output | No | Yes |
| USB | Micro-B or A male | B |
| Soundcard | Is the soundcard itself | Uses PC soundcard |
| Audio cables | Shorter | Longer |
| Modulation relay | Solid SPST | Mechanical SPDT |
| Separated grounds | No | Yes |
Photos
Features
- Simple assembly
- All parts are SMD
- Designed for SMD reflow
- 3.5 jacks
- 3D printed box
- SMD LEDs + light guides on the top side
- power supply from USB
Circuit diagram
Notes
- R1, Y1, C2, C4 are not assembled in case of CM108B
- Althrough preferred chip is the CM108B, is possible to assembly older CM108
- The 93C46 is optional but recommended
- The JP1 - Turns ON/OFF the audio mixer - please consult datasheet of the CM108B
- I used LCBB-600 also instead of R9 and R16
- R11 and R17 are for possible coarse attenuation
Connecting to the radio
- MOD - Modulation output to the microphone input of radio
- PTT - Push to talk output to switch Radio to the transmit (active low)
- GND - One ground (ground plane on the bottom layer)
- MIC - Modulation input from headset
- BIAS - Microphone supply (from soundcard, not from radio)
- CW - CW output to key to the radio
- REC - Recording input to record band traffic
LEDs
- PWR lights up - Device is powered from USB
- PWR blinks - Soundcard is playing or recording
- PTT - Push to talk is active (SSB and also CW)
- CW - CW in the rhytm of Morse code
- MIC - The SSR connects MIC to the MOD (off/disconnected if CQ is active)
Trimmers
- CQ - Modulation level to the Transceiver
- REC - Record level attenuator
PCB
Gerber files to order PCB at Elecrow or jlcpcb.com.
Box
STL files for 3D printer.
Recommendations:
- Nozzle 0.4mm
- No support, maybe brim in case of bad adhesion
- Layer height - first 0.3mm, others 0.2mm
- PETG or PLA
Light guides are made from transparent PETG filament.
Parts
Bill of material for tme.eu.
(not including cables)
Set USB string to EEPROM
Only if the 93C46 is installed. From menu Setup, CW keying, Davac5 options.
