KIO3B upgrade now on Elecraft Order Page

Eric Swartz - WA6HHQ, Elecraft

We are now ready to take orders for the KIO3B upgrade kit for the K3. This upgrade Includes: KIO3B 3 board set (KIO3B main, digital and audio boards), RJ45-RS232 cable, USB cable, h/w and manual.

Its can be found on our order form at:

(There is also a link to it on our order page table of contents.)

See our KIO3B Upgrade FAQ for details:

The new KIO3B (standard on the K3S) adds high performance USB sound and comm port capabilities to the K3, eliminating the need for RS232 and 3.5mm analog audio cables to the PC.  Basically one USB cable to the PC (included with the KIO3B) handles this all, eliminating both RS-232 headaches and potential RFI issues with analog audio paths.

The KIO3B also includes all of the analog and digital capabilities of the prior KIO3 (Line in/out, headphone, mic, Aux Conn. and RS-232).

If you are using an existing P3 with the upgraded K3 and KIO3B, you will also need to purchase the CBLP3Y, which provides a path to the P3's RS-232 connectors from the RJ45 jack on the KIO3B, and supports one USB cable connection between your PC and the K3 for all comm port I/O and audio.  (New P3s are shipped with this cable.)

The KIO3B still also supports all of the old methods for rs-232 connections between the K3, Computer and P3, so you can just drop it in to your current hook up without using the USB comm port, if desired.

The KIO3B Upgrade FAQ linked above has diagrams showing these two main ways of connecting the KIO3B to the P3 and computer.


Tom Hellem

Will this new upgrade eliminate the need for an outboard box like Microham
or Rig-Blaster for someone wishing to send computer-generated WAV files
to the microphone input of the K-3? 




What is the source for the audio with the KIO3B? Since the K3 uses DSP, I assume that there is a digital stream of data that is converted to analog for audio output. Is this analog audio re-digitized for output to the USB or is the digital data before it is converted to analog send out the USB eliminating a D/A and A/D transform? 

Is the USB data stream compatible with non-Windows computers, such as Linux or Mac?

73 and Happy Holidays,



What is the source of the audio data? Since the K3 uses DSP, I assume that there is a digital audio stream that is converted to analog. Is this analog stream re-digitized or is the digital audio output from the DSP sent directly to the USB?  If the former, do the back to back D/A and A/D conversion degrade the signal?

Does the USB port support FSK keying?

Are the USB input and output recognized by Mac and Linux?

73 and Happy Holidays,
Mark, N8ME