IU8BBM Lynx Interface

A Yaesu FT-8x7 DIGI/CAT/CW isolated interface by IU8BBM - Luca Gallucci.



Italian Language Clicca qui per l'articolo in Italiano.


The IU8BBM Lynx (named after the latin name of the constellation of the Lynx , read it like “links”) is a fully isolated interface for Yaesu FT8x7 series, useful for all Digital Modes, CW and CAT link with the radio. The Lynx implements a full isolation between radio and PC, both on the CAT and AUDIO signals, thus avoiding ground loop issues and noise to and from the radio itself.

Follow the technical specifications:

  • Yaesu FT-817, FT817(N)D, FT-857, FT-857D, FT-897, FT-897D compatible;
  • Isolation on AUDIO side, with two 600Ω audio transformers, high passband (>>3.5kHz), cermet potentiometers volume regulation;
  • Isolation on CAT side, with an application specific integrated device with not only provides a logic level conversion between RS232(+-3,6,12)/TTL levels (38400baud compliant), but also give a galvanic isolation between PC’s and Radio’s grounds;
  • Isolation on PTT and CW, with a double channel optoisolator;
  • Radio powered, no need for external power supplies;
  • Boxed in grounded aluminum enclosure (32x44x7mm), and wired with Foiled-UTP Cat6 cables (high passband aluminum foiled twisted pairs) thus providing a full electric and magnetic isolation;
  • PC connectors: 1mt cables with DB9(RS-232) and 2xAudio Jack RTS Stereo 3.5mm (Mic, out on “tip” pin and Spk, in on “tip” pin); RTX connectors: 50cm cables with mini-din6p(data), mini-din8p(cat), jack3.5mm(key);
  • Explicative sticker for a quick reference for cable wiring and leds;
  • The interface works both with standardized +-12V RS-232 levels and 0-5V usb serial adapters.

Electrical Isolation on:
AUDIO    -> Transformer
PTT/KEY -> Optoisolator
CAT        -> RS232 Isolated Transceiver




Every interface is sold with an english manual including:

  1. The Interface
  2. Setting up the software (including memory programming)
  3. Connectors Wiring
  4. Layout and Schematic

The manual include, a complete description; all information to connect the cables and setup the interface with Mixw, Ham Radio Deluxe and Chirp (for memory programming); connector wiring (upgrade the interface for other radios); pcb layout and schematic for repairings and modifications.

Links for complete documentation follow:

Click here to download the Manual v1.2 for V3.2 boards

Click here to access to Lynx Documentation

Click here to the official webpage



Interfaces are sold directly for 60€+shipping(24/48h shipping courier, prices vary: Italy 7€); contact me at iu8bbm [at] gmail.com.

Every board is fully tested with a bidirectional BPSK QSO and a CW keying test. I can give, free and lifetime support; basing on components availability, I can give eventually free repairations.

For mere legal issues, the interface is sold with warranty exclusion formula, it's sold "as is" so the eventual bidder with his offer accept unconditionally the exclusion of any warranties and declination of the right of repossession.

Anyway this doesn't imply my full availability to full supportn and eventual repairations.

Want to save money? If you're following an auction or a "buy it now", before placing any bid, mail me at iu8bbm [at] gmail [dot] com !