DAX I/Q level is too high comming out of stream for feeding MAP65. Can I adjust it?

Paul Sokoloff

DAX I/Q level is too high comming out of stream for feeding MAP65.  Can I adjust it?

Mike va3mw

Have you tried to adjust it in DAX on the Slider in RF streams?

Paul Sokoloff

Thanks for your reply.  RX streams is for audio only. 

IQ streams does not have a slider.  Cannot find any level control for that parameter.

Paul 

Mike va3mw

I am sorry, I misread.

Tim - W4TME

The DAXIQ output is fixed for a 0 dB output gain level.  There is no way to change the gain level (volume) of the DAXIQ channel.

Paul Sokoloff

I went into "DAX RESERVED IQ RX 1" and lowered the levels to 25%.  I also unchecked "applications exclusive control"  There is no difference in the level noted in MAP65.

Tim - W4TME

Never use or change any the reserved DAX audio devices.  Only change the ones that are not labeled reserved.

Paul Sokoloff

Also note I changed from MME to WDM and still no change.

Paul Sokoloff

OK went into Sound tab and then into Recording tab.  That is the only place I found a DAX IQ 1 non reserved device.  I had changed that and no change in map65.

Paul Sokoloff

Do I need to reboot after change?

Tim - W4TME

You shouldn't need to reboot.  I'll need to investigate why the gain is fixed and not adjustable in the Windows sound device properties.

Kevin

Is there an update on this? I'm thinking I would like to adjust the level coming into CW skimmer to reduce it's sensitivity to noise. Some nights with few signals I'm running 2500 decoders while skimmer tries to decode noise.

Or maybe there's an adjustment within skimmer I've missed.

Tim - W4TME

The gain if fixed because the DAXIQ comes out of the FPGA and there is no facilities to reduce it.  Also, I run CWSkimmer, SDR-Bridge and a 6700 several times a week and I do not see this behavior at all.  I suspect that there may be something set in CWSkimmer that is causing this behavior.

Kevin

It seems to be the noise level causing it which is why I was hoping to back it down a little bit. Here's 80 meters this morning. The difference as I can tell is the noise level is down quite a bit this morning. I'll check with the author and see if I'm missing something there.

Tim - W4TME

Check the decoding thresholds and if you are only viewing verified calls in CW Skimmer.

Kevin

I have Verified Calls + Show 599 checked. I see no place to adjust decoding thresholds. Just sent an email to Alex and will post if he has a solution.

Kevin

Alex's response:

There is no point in adjusting the I/Q level, unless it is so high that the signal is clipped. CW Skimmer looks at the peaks above the noise floor so multiple yellow circles mean that there were multiple peaks rather than the usual wideband (flat) noise.

Hmm. Not sure what to make of it but it seems to be like this by design.

Thanks for checking Tim.

Kev

John - K3MA

I have a similar issue with the DAX IQ level into MAP65.  In my case it is too low.  On 2M EME it reads about 13% in the MAP65 level display and they recommend a level at 20-30%.  Is there a way to increase the DAX IQ level?

Tim - W4TME

The level for DAXIQ is fixed.

Kevin

Is there a standard for I/Q? Is it always fixed or is it FRS's implementation? If it is just an implementation issue can we turn this thread from a question to an idea?

K