value at center of filter skirt in SSB

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  • Updated 3 months ago
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  • (Edited)
When in USB or LSB mode, the filter skirt displays the low and high pass values as well as a center value.  For example in USB with the 2.7 filter selected, the skirt shows 100 at the low end and 2800 at the high end.  The meaning of these is clear.  It also shows 1.5k at the center-top of the skirt.  What does this value represent?  How is it calculated?  How do you use it?   Thanks.

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Ken, K2KXK

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Posted 3 months ago

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Larry - W9FLA

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Official Response

Three of the numbers represent/describe the location of the filter parameters with respect to the carrier or zero frequency.  Two are the corner frequencies of 100 Hz and 2800 Hz.  The 2.7 kHz (2800 – 100) represents the filter bandwidth.  The top 1.5K number represents the location of the filter center frequency with respect to the carrier and shown with two significant figures.  It can be calculated as:


Fl+(Fh-Fl)/2 i.e 100+(2800-100)/2=100+1350=1450 or approximately 1.5K