24 kHz CW Skimmer with the Icom 7610 | How To

Icom has really made it easy to have CW Skimmer working with the Icom 7610. First I installed the Icom 7610 I/Q package for HDSDR and got it working. See my article: Icom 7610 HDSDR and Icom I/Q Package. After having it for a while I decided to give CW Skimmer a try and wow! Not only easy, but it works so good. The decoding on CW Skimmer (CWS) is amazing. If you like CW or want to learn more about CW, this is a program that will help.

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CW Skimmer, Null Modem Emulator, Hi-Fi Audio Cable

See my previous article on HDSDR, you need it going first. To get started on this little project you need CW Skimmer, Null Modem Emulator, Hi-Fi Audio Cable installed and setup. There was really not much to it.

All of the download links are in the document. Page 4, near the top.

Install them and if the Null Modem Emulator created COM ports with numbers of 20 and under, it’s good to go and I think this is usually the case. Nothing else needs to be done with it.

The Hi-Fi Audio cable properties need to be changed to 16 bit, 192000 Hz. That’s it! (see video below)

HDSDR Minor Tweaks

In HDSDR for it to operate with CW Skimmer there are a few minor tweaks that need to be done. If you followed my previous article, Icom 7610 HDSDR and Icom I/Q Package, that’s a good beginning and you won’t have any trouble.

There are only 6 small steps and I won’t list the changes to it here because they are nicely put together in Icoms PDF. It’s under the Operating Guide section of the PDF on page 8.

CW Skimmer (CWS) 24 kHz

On page 9 of that same PDF you see some steps to get CWS going and talking to HDSDR and the radio. There are only 4 steps. Now how easy it that.

Icom really simplified things.

Things to Watch For

  1. After starting CWS you may hear a tone and see a line in CWS where your marker is. To eliminate it, just increase the I/O Gain in HDSDR. You’ll see a slider for it. (see video).
  2. Frequency is flashing in CWS. Although it is not a problem, it may be annoying to some. After using it for a while I decided to setup CWS (Omni-Rig) with my CI-V cable and seperate COM port. No flashing or flickering of the frequency in CWS now. (see video).
  3. If you decide to keep CW Skimmer, it’ll cost $75.


A big thanks to subscribers and everyone who posts questions, comments and sends emails with ideas and suggestions. I sincerely appreciate it and hope this website helps Ham operators.

If you have a question or suggestion, please comment below. I will do my best to answer it and your experience will help others as well.


Rich, K0PIR


Preparations for using the IC-7610 with the HDSDR application/IC-7610 HDSDR Operating Guide

K0PIR:  Icom 7610 HDSDR and Icom I/Q Package

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I'm an Amateur Radio enthusiast. I love the hobby and experimenting with radios, antennas and software. On my YouTube channel I upload videos on the Icom 7300 and Icom 7610 along with Ham radio software programs. I hope to inspire people to try new things in Amateur Radio.

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2 years ago

Hello Rich
I finally have HDSDR and CW Skimmer working with my IC-7610. My WIndows 10 Lenovo computer and HDSDR did not see the new com0com ports. Finally I removed com0com and loaded Null Modem Emulator by Eitima and no problems assigning two new ports for HDSDR. Also CW Skimmer did not have 7610 in CAT setting so I stayed with “Kenwood: and the “flicker” freq readout
Again MANY Thanks

2 years ago

Hi Rich,

I have set all this up and it’s working fine. However my HDSRD has no I/O gain selection available, so can’t make minor tweak to CW skimmer. Have you faced this? Is there some other setting which prevents adjusting the gain?

Jarkko, OH6NEQ

Tom Johnson
2 years ago

Have you explained how to setup CWS with the IC-7300?

2 years ago

RE: Frequency is flashing in CWS.

For me I found that instead of using Kenwood, the flashing stopped if I configured the Cat Interface to use “ZS-1”.

73 de AI4Y

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