DigiKeyer-2 external soundcard with CAT interface

More than just a soundcard interface - DigiKeyer-2

Significant differences to the predecessor microHam DigiKeyer:
- Winkey Chip for precise morse keying added
- Foot switch added
- Support for pseudo-FSK (fldigi) and OOK (Audio On/Off keying by cocoaModem)
- AF output for integration with the Micro-2R SO2R station controllers

The DigiKeyer-2 is much more than an interface, because it is an own, self contained soundcard. Together with the other integrated components like CAT interface and PTT/FSK/CW keyer this is a very versatile interface for all special modes. Use RTTY, Fax, SSTV, Echolink, PSK31, MFSK, Olivia, WSJT, APRS and many more, everything which is supported by a soundcard.

What is Pseudo-FSK/Pseudo-CW/OOK?

For 'real' FSK keying one would normally require a true UART chip in the computer (parallel to serial converter, COM-Port). With a virtual COM port such a device is simulated by the USB driver, but only with some problems. Depending on the load of the computer the timing of keying can vary (jitter) or be delayed (latency). This leads to not very clean telegraphy keying. With RTTY/FSK the characters might be illegible on the receiving side due to timing errors.

Now some multi mode programs (e.g. fldigi or cocoaModem (MacOs)) have found a good solution to this USB driver issue. Instead of toggling a handshake line of the virtual comport, an audio signal is sent (or not) to the right channel of the soundcard output. An additional hardware decoder within the interface detects the presence or absence of the tone and uses this information to key the FSK or CW line to the radio. With cocoaModem this mode is called OOK, Audio On/Off Keying

This leads to a much more precise timing with FSK and CW. Especially when using high speed telegraphy or QSK this is very beneficial. When using RTTY/FSK you can be sure that all characters are sent with the proper and consistent baudrate.

Of course the radio must support FSK keying to use this function with RTTY. When using AFSK this problem does not exist.

• With the integration of a high-quality soundcard you have several advantages:
• The internal soundcard remains free for other tasks, e.g. system sounds
• No noise like often seen with soundchips on the motherboard
• Developed by radio amateurs for radio amateurs: much better dynamic range and less noise as with simple consumer cards
• No need to change soundcard connections on your PC
• Two line-in channels for AF from Main and Sub VFO (where supported)
• Better AF quality with notebooks, where the microphone input does not offer the right impedance
• Support for practically all OS due to native USB soundcard drivers
• Only one cable between interface and PC: a standard USB cable
• microHAM USB Device Router and microHAM Device Configurator are compatible with all 32bit and 64bit versions of Windows 7, Windows 8, Windows 10, Vista, XP, 2000 and 2003.

Of course all connections between radio and PC are electrically isolated to avoid noise loops. Between the DigiKeyer-2 interface and the PC just a standard USB cable is required. And also from interface to the radio it's only one cable, which usally connects to the rear connections of the radio. This greatly simplifies station setup.

The integrated CAT interface transmits frequency and other information between PC and radio, most manufacturers are supported: Icom, Kenwood, Yaesu, Elecraft, JRC, and TenTec. Depending on type a level conversion is done by the interface.

With just one cable between DigiKeyer-2 and radio all connections for CW, PTT and FSK keying are done. Further the interface offers two more time delayed PTT lines for power amplifier and pre-amp keying.

A connection on the rear side of the DigiKeyer-2 is used for a PS/2 keyboard (full or 10 Keypad, see below). With this keyboard pre-defined texts can be recalled for digital modes like RTTY and for CW.

A special AF output serves to connect to the Micro-2R SO2R station controller by microHam. This allows you to integrate the DigiKeyer-2 perfectly into your SO2R station.

The cable between DigiKeyer-2 and radio is individual to each radio model and must be ordered separately. We offer cables for most radio models. If the interface will be used on several radios, just order one cable for each radio.
Weight 1.1kg, Size 165 x 44 x 110mm. We offer an optional 10 keys keypad MK-KEYPAD, see below.

List of cables for microHAM "digiKEYER", "USB-2" and "USB-III" interfaces

microHAM Cable

DigiKEYER List of cables and schematics

10-Keypad

The 10 Keypad is directly connected to the microKEYER and allows control of various CW functions, like recall of stored standard buffers, adjusting speed and many more. The RTTY functions require a full PS/2 keyboard (a USB keyboard will not work!).