l_u3_front_panelThese USB Interfaces provide a solution to the lack of available Serial (COM) ports on laptop and newer desktop computers for controlling your radio.The USB interface III includes full optical isolation of all control signals (radio control, CW,  PTT and Squelch) and built-in USB soundcard with front panel level controls for transmit via your transceiver’s Accessory audio input and the constant level (pre-volume control) audio output.microHAM USB Interfaces have built-in hardware support for your radio – you no longer need additional level converters like CT-62, IF-232, FIF-232, CT-17.   USB Interface III includes support for CW keying (DTR) and PTT (RTS) as well as a detector/driver for pseudo-FSK and QSK CW on the soundcard’s right audio channel for use with FLDIGI on any platform. USB Interface III uses same cable as USB Interface II or DIGI KEYER.

Just one USB port for audio and Control
Complete “Computer <-> Radio” electrical isolation
– bidirectional transformer isolation between sound card and radio
ALL digital signals: Radio Control, CW, PTT, FSK, and Squelch,
optically isolated from USB port
Standard Sound Device – no custom drivers:
The USB Sound Device is an industry standard device recognized by
Windows, Macintosh OS 10 and LINUX. There are no custom device
drivers to install and no compatibility problems with your applications.
Ultra low noise:
– The sound circuits are designed with special attention to low noise
Receive noise floor is better than -90 dBm (typical) in 600 Ohms.
– 87 dB (typical) dynamic range rivals that of professional products.
– Special circuit design maintains full dynamic range and low noise floor
with all radios – both high level and low level outputs.
Independent transmit and receive clock
– Transmit clock: 32000, 44100, 48000 Hz
– Receive clock: 8000, 11025, 16000, 22050, 32000, 44100, 48000 Hz
– sampling rates are native: no up/down conversion or “rounding” errors
Right channel audio detector and FSK/CW driver
FSK output for FDIGI “pseudo-FSK” mode
Provides a “hard keyed” CW output for software that generates
only audio (sidetone) CW
Support for all radio control standards (CI-V, FIF-232, IF-232, RS-232)
– fully supports Icom, Kenwood, Ten Tec, Yaesu and other radios
– no separate level converter required
Squelch input for signaling to computer
– two inputs, one is active low, second is active high
– ideal for Echolink and remote interfacing applications
No external power adapter for most transceivers
– Computer part is powered from USB
– Radio interface is powered from transceiver or transceiver power supply
Strong immunity to RFI
– integrated chokes and filters for best RFI immunity
– advanced shielding and circuit design for RFI product suppression
Quick change connectors
– USB
– Radio – DB15
LEDs for easy visual feedback of CAT, CW, PTT, SQL
Metal/Aluminum case, powder coated and silk screened
Free software upgrades via the internet

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