IQ frequency in DAX does not track with radio frequency.

Tim K9WX · March 2023

I have been trying to set up CW Skimmer to work directly with the my 6600 without using a third party application like Slice Master. And I am finding a problem with the DAX IQ frequency failing to track with the radio frequency.

For instance, I have one slice open to a 40m frequency and I QSY to 3.546 by typing the new frequency into the slice flag. SSDR, DAX IQ and Skimmer will all show the same frequency. I then tune up the band to 3.548 using my FlexControl; SSDR and Skimmer track with each other but the IQ channel in DAX stays at 3.546. See the screenshot below. Thus, the signals in Skimmer will be off frequency by 2 kHz, the amount of the offset between the radio's frequency and the DAX IQ frequency.

I get a similar result if I use a Maestro to tune up the band.

Sometimes DAX IQ will track and sometimes it doesn't but it almost always fails to track when I use the FlexControl or the Maestro, the most common ways I tune the radio. And it doesn't matter if Skimmer is open or not.

Is this is something with SSDR that I either have set up incorrectly? Or, perhaps a bug.

Tim K9WX

Erik Carling EI4KF · March 2023

Are you using the SoftRock setting for CW Skimmer Hardware Type?

BTW the IQ stream frequency in DAX should be the Panorama centre frequency, not the VFO frequency. It will remain static until you tune to the Panorama edge or you zoom in/out.

I use CWS without 3rd party assistance and it works fine so I doubt there is a bug.

My experience, but others may know differently.

Tim K9WX · March 2023

Thanks Erik. I was not aware of the centering in the display detail and that may explain what I am seeing. In which case getting this to perform like I want may be just a case of technique on my end.

And, I am using the SoftRock-IF setting for Skimmer hardware type. Is that not a good choice?

Tim K9WX

Erik Carling EI4KF · March 2023

Hello Tim,

Change CW Skimmer to SoftRock, not SoftRock-IF. I think this is where your issue stems from.

I might add that CW Skimmer without a 3rd party link to Flex is not really optimal because CWS was designed a long time before SDR became popular. Whether you ultimately decide to give it some help or not, look at

NN4ZZ CwSkimmer Bridge setup 19-Feb-2020.pdf

At the very least, it will show you some important settings for the Skimmer.

Erik.

Tim K9WX · March 2023

The SoftRock hardware type option in Skimmer calls for an LO number to be inputed. This option is grayed out for SoftRock-IF. Do you have a suggestion for what this number should be when operating Skimmer on a stand alone basis?

I will take a look at the SDR Bridge setup file. I don't recall if I tried that when I first started with Skimmer. I have tried to operate Skimmer with SliceMaster but with inconsistent results. I believe I have Skimmer installed in the default location (C:\Program Files (x86)\Afreet\CwSkimmer) but SliceMaster would not always launch Skimmer when I would switch to CW and if it would launch a first instance it would sometimes not launch a second instance for a second slice. Despite having "launch by mode" and "CW" selected on the tabs for each slice and despite having a DAX IQ channel assigned to each slice.

Tim K9WX

Erik Carling EI4KF · March 2023

The Lo number is your Panorama centre frequency, the same as you see in DAX IQ Streams.

Stand alone, as I said, is not optimal Tim. There is no interface between Skimmer and Flex. With SDR-Bridge, the LO is set for you and is dynamically controlled. Plus the Skimmer will know the frequency of the VFO.

I recommend you try it!

Erik.

IQ frequency in DAX does not track with radio frequency.

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