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OHIS User Adapter kit


The OHIS User Adapter is an Open Source (free like speech) design of an OHIS User adapter (creatively named).  The design files are available at:

This kit requires assembly:  Assembly Guide

In stock (can be backordered)

Assembly Options

  • Let Halibut Electronics assemble the kit for you.

Product total

Options total

Grand total

This is a kit of all the parts required to make the Open Source (free like speech) OHIS User adapter.  The open source design files are available at:

This kit requires assembly:  Assembly Guide

What is this thing?

The OHIS User Adapter Kit makes a User Adapter (see the OHIS Overview tab for details).  This kit:

  • Has an OHIS compliant User port, to be connected to an OHIS compliant Radio device.
  • Microphone: either Dynamic or Electret
  • Headphones: Conventional 3-pin TRS headphones, or CTIA 4-pin TRRS headsets.
  • PTT: Built-in button, or external switch.

How is this different from the HHI User Pro?

They accomplish similar things.  They are both User Adapters to convert your headset (or other microphone/headphones/PTT combo) to an OHIS compliant User connection.

The OHIS User Adapter (this product):

  • Is Open Source.  Anyone can source their own parts and make and improve it.  Or, to save the hassle, buy the kit from Halibut Electronics.
  • Is a kit that requires assembly.  It’s a simple kit: entirely through-hole, no surface mount.  It a good first-time learn-to-solder kit for clubs or individuals.
  • Is configurable for the most common headset types:
    • 2 connector 3-pin TRS headphones and microphone, or 1 connector 4-pin TRRS headset.
    • Electret or Dynamic mic elements.

The HHI User Pro:

  • Is a completed, assembled “pro level” product, not a kit.  It’s in a full case, not just a stack of circuit boards.
  • Includes a built-in microphone VU meter to aid in adjusting Mic levels
  • Is more configurable, but less hackable.
  • Is a Halibut Electronics branded product, with Halibut Electronics support, not open source.
Weight 0.1 lbs


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OHIS Overview

A quick overview of the Open Headset Interconnect Standard, or OHIS:

An OHIS Radio Device adapter, like the HHI Radio Pro, converts the radio’s native electrical and physical connections to the OHIS standard, and provides an OHIS Radio port.

An OHIS User Device adapter, like the HHI User Pro, converts any headset’s native electrical and physical connections (or other mic, headphone/speaher, and PTT) to the OHIS standard, and provides an OHIS User port.

OHIS allows any OHIS User port to connect to any OHIS Radio port, regardless of the electrical or physical properties of the devices behind them.

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