[TenTec] Filters, amps and IMD, etc,

[Lee Crocker]

It is my understanding that the problem is one of a
fixed gain amp, and variable insertion loss for the
filters.  When the gain and loss are summed it gives
you variable gain between filter choices.  But in 
general there is a several dB increase in total stage
gain when you switch in the cascaded filters.   More
stage gain=reduced dynamic range.  

It seems the worse case is the 500hz filter which has
the smallest insertion loss.  The reduction in IMD was
less of a problem for the 250 filter which has a
higher insertion loss.  I notice a very slight
decrease in stage gain when I turn on my 250hz filter,
and I'm not sure I detect any improvement in S/N as I
would expect.  I run my Orion almost all the time with
the 250 off.  I've never really found a case where it
was of any significant benefit. 

73  W9OY  


		
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