[Lowfer] Spectran question

JD listread at lwca.org
Fri Apr 4 20:58:16 EDT 2014


>>> ...you do not need to use the radio's filters when you use Spectran.  In 
>>> fact, the filters cause a small drop in the signal, so there is an 
>>> advantage to not using them.

Sometimes, perhaps, but this is not universally true.  Depending on your 
receiver's architecture, its filters can keep noise sources from using up so 
much of the radio's dynamic range, keep the blanker and AGC from having to 
work as hard, and/or reduce distortion in the audio chain...all of which can 
adversely affect display or decoding software.

I see this a lot of the time with Argo, and also when watching Bob with WSPR 
this past winter.  The SNRr of the latter software was even less meaningful 
than usual under narrow-CW filtered conditions, but copy was distinctly more 
reliable.

John 



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