Confused about pre-select filters and WIDE receive mode

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  • Updated 2 months ago
My goal is to be able to use a slice for ALE scanning, bypassing all filters so the rig is not engaging and disabling filters 2 to 5 times a second.

My understanding about filters is that when the slice is in WIDE mode, pre-select filters are disabled.  However, when I use MARS-ALE to scan frequencies, I still hear relays clacking as the frequency moves to different areas of the spectrum.  Note that I am scanning frequencies outside the ham bands.

Did I misunderstand how filtering works on the 6600?  Is this possibly an issue because I have the MARS filters installed?  Is there any way to simply bypass all filtering until the radio is put in transmit, then disengage the filters on receive?

If I 6600 will not work for this application, I have another question.  Is there a way to have the radio frequency set from external software ONLY when it goes into transmit?  My reasoning for asking this:  I can set up MARS-ALE to scan and receive via another SDR, but key the flex when an active frequency is found.  However, doing this currently will (obviously) transmit on whatever frequency the 6600 is set to, which does me no good.

Any thoughts and comments welcome.

73 - David, AG4F
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David Salomon

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Posted 6 months ago

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Joe N3HEE

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I would also like to understand how and when band pass filters are switched in and out of the signal path.  I would like to know about insertion loss of engaging the band pass filters.  I suspect it is pretty high.  I notice significant improvement in signal strength and signal to noise ratio when WIDE is engaged on 160 meters.   
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David Decoons wo2x, Elmer

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zoom out on the panadapter until the width is wider than the bandpass filter. It will switch out of circuit and WIDE will be displayed in the upper right of panadapter display.

Dave wo2x

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Joe N3HEE

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Hi Dave.  Yes, I understand that part.  I guess I'm more interested in performance with or without bandpass filters in the signal path.  How do they make up for insertion losses ?  I've been paying close attention to DX signals on 160 meters CW and I am seeing signal degradation with filters inline on 160 meters. Not so much signal strength reduction but signal to noise degradation.  Seems like noise is introduced when bandpass filters are inline.  I have not tested on other bands.  I am opening a ticket with Flex.  Joe N3HEE
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David Decoons wo2x, Elmer

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Can't help you there as 160 is the only HF band I do not operate, so never tested there.

73
Dave wo2x