[Elecraft] Rx filter attenuates at 100 Hz bandwidth

[Eric Manning]

  I think Eric S. said once, that the filter   was not designed to 
work well with a filter bandwidth set as narrow as 100 Hz.

I think he recommended 250 Hz as the narrowest filter width which 
wouldn't cause major attenuation.

I had exactly the same thing - serious loss of gain with FL4 at 100 
HZ, so I opened it up to 250 Hz and the problem went away.

WHY do many of us  set our narrowest  cw filter to 100 Hz? Because 
the K2 manual - last Spring's version, anyways -  tells us to do it 
[!]

eric

original message ---
============


From: "Brent Sutphin" <bsutphin@triad.rr.com>
To: <elecraft@mailman.qth.net>
Date: Mon, 16 Dec 2002 19:04:01 -0500
Organization: Home
Subject: [Elecraft] Filter Crystals

I have K2 # 2571.  I am one of those people who want my rig to work as =
well as possible.  I am having trouble with the decision whether or not =
to replace my filter crystals.  The filters are set up for a pass band =
of 1.5khz, 700hz, 400hz and 100hz.  Here is the symptom I would be =
trying to eliminate. I loose 10-12db of signal strength when I switch to =
the narrow 100hz filter.  Is this normal?  I set my filters using =
Spectrogram and the signal loss was measured with this software.  Any =
help would be appreciated.

Thanks
Brent  =20
-- 
Eric Manning   VA7DZ VE3DPV
K2 #2561 "Pauline"

If God intended you to use SSB, He wouldn't have given you a fist. Or 
two lungs.