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 | A |
| Soundcard | Is the soundcard itself | Uses PC soundcard |
| Audio cables | Shorter | Longer |
| Modulation relay | Solid SPST | Mechanical SPDT |
| Separated grounds | No | Yes |
Photos
Davac 5 inside box with cables
Recommended assembly is stencil, paste and reflow oven
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
Circuit diagram of Davac 5.0
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
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
