Introducing “The Serial Box” by N6TV

The “Swiss Army Knife” of interface boxes

Serial Port Splitter / Amplifier Interface / FSK, CW, and PTT keying interface / Breakout Box

See also “The Y-BOX” – a K3/K3S ACC port splitter

Front View Rear View


The Serial Box USB (S-BOX-USB) with built-in genuine FTDI USB-to-Serial adapter:


The Serial Box (or “S-BOX”) makes it easy to connect multiple devices to any transceiver – no custom cables or splitters required.


  1. Any control device with a serial port or available USB connector (PC, MAC, Linux, microHAM, RemoteRig)
  2. Any automatic amplifier designed to monitor serial port traffic (Elecraft, ACOM, SPE)
  3. Any automatic antenna controller that monitors serial port traffic (SteppIR, KRC2, ShackMaster SM-8)
  4. Any other device designed to track frequency changes by monitoring the transceiver's serial port (e.g. RFSpace SDR-IQ)

Connection diagram

The S-BOX also includes four (4) independent open collector keying circuits that can be internally wired to the TXD, DTR, or RTS pins of any serial port. These can be used for:

A single serial port can control the radio and key CW and PTT over the DTR and RTS pins of the same cable, providing a convenient way to key transceivers that do not have this feature built-in.

The S-BOX may also be used as a “breakout box” for any device with a 15-pin D-SUB connector (DA-15 or DE-15), including ACOM and SPE amplifiers, the FlexRadio FLEX-6000™ series, and the 4O3A Antenna Genius. You can connect any pin to any of the four independent RCA connectors.

Click to review S-BOX Features and Wiring Examples

See the reviews here

For ordering and pricing info., click here

Order form direct link here

Limited quantities ** IN STOCK **

What's Inside? Click photo to enlarge – click schematic to download PDF

Inside View Schematic

S-BOX Benefits

Click the links below to review the benefits of using the S-BOX with each of these products:

Every Serial Box Provides:

Optional cables:


“The Serial BOX” – the simple solution to your high tech transceiver interface challenges

Bob, N6TV

4 September 2018 07:24 UTC