CW SKimmer - DAXIQ includes TX signal

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Is it normal for DAXIQ to include the TX signal?  See the CW Skimmer snapshot below while sending my call.   Skimmer also tries to decode it in several locations as well (you can see 2 places below)

Is there a setting some where I'm missing to mute the DAXIQ signal during transmit?  

Regards, Al / NN4ZZ


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Al / NN4ZZ

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Posted 5 years ago

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Dudley - WA5QPZ

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Your are not trying to send I/Q tx back to the radio are u?
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Al / NN4ZZ

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Dudley,
Not intentionally.   Here are some more screen shots showing my setup.  Also some new clues.  See the comments below.  

Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com







The V keyed in this snapshot below is with TRANSMIT disabled, it follows the sidetone. 





In this snapshot TX is enabled and RF is generated.  There are 2 V's being keyed and they show up on multiple frequencies.  The output is much wider.  It looks like the skirts of the RF signal are being received and sent to Skimmer via DAX IQ.  




RF screen capture....




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Tim - W4TME, Customer Experience Manager

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Official Response
The radio is full duplex; it is receiving when you are transmitting
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Al / NN4ZZ

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Tim,
Thanks that explains a lot.  When I have the RX antenna and TX antenna the same (ANT 1) the SmartSDT GUI display shows a very wide transmit signal. See snapshot 1 below.  And this is also when CW Skimmer shows my signal appearing several places across the display frequency.   See snapshot 2 below.   I guess the wide TX signal being displayed is normal.  Is that correct? 

As an experiment I set the RX antenna to ANT 2 (where there is NO antenna connected).  The display shows a much cleaner and narrower signal when I transmit.  See snapshot 3 below.  In this scenario CW Skimmer only shows my signal on the frequency where I'm transmitting.  

So if the wide TX signal I'm seeing in snapshot 1 is normal, then I can expect CW skimmer to have the display I'm seeing.   Does this sound correct?  Is this what others also see?


Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com



************** Snapshot 1 ************* 







************* Snapshot 2 ***************






************* Snapshot 3 ***************


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Tim - W4TME, Customer Experience Manager

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"So if the wide TX signal I'm seeing in snapshot 1 is normal, then I can expect CW skimmer to have the display I'm seeing.   Does this sound correct?  Is this what others also see?"

Yes this is normal.
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Greg

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Al,  What happens if you use ANT2 for the skimmer panadapter and ANT1 for your transmitting and use a relay to ground ANT2 during TX?


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Al / NN4ZZ

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Hi Greg,
I only have one antenna connected to the radio and it is on ANT1.   No antenna is connected to ANT2 so I can't use it for normal CW Skimmer RX operation.  

During my test I set the RX antenna to ANT2 just to see how much it would reduce the signal level of my TX signal.   And It did reduce it quite a bit since I don't have anything connected to ANT2.  Even without an antenna connected, my TX signal is picked up and displayed on the panadapter (as seen in snapshot 3 above) and CW Skimmer.   And at the reduced level, my TX signal only appears at the expected frequency on the skimmer display.   But since there is no antenna on ANT2 none of the other signals are displayed.  

Based on Tim's feedback, other CW Skimmer users on the 6700 should see the same thing (as in snapshot 2 above) when transmitting and receiving on ANT1.  It's not really a big issue, I just wanted to understand why it was happening and verify that it was normal.   

Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com

    
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Greg

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Hi Al.  I do see what you are seeing.  It seems by programming that the IQ channel in use should be able to be temporarily disabled during transmit.  That may get hard with QSK and fast speeds and maybe not possible.  But it should be doable at lower speeds or non QSK semi break-in.

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Steve - N5AC, VP Engineering / CTO

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This just slipped my mind when we did DAX IQ.  We can mute it at the exact time that you are transmitting to avoid this.  I'll put this on the to-do list.
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Greg

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Thanks Steve!