Date: Fri, 12 May 2000 13:26:10 -0400
From: "'Geri' Kinzel, DK8KW" <DK8KW@compuserve.com>
Subject: LF: Optimal width for LF?
To: rsgb_lf_group@blacksheep.org
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Petr asked:

>What bandwidth do you use and what is the
experience?<

I use 100 Hz bandwidth for normal CW as well as for Slow CW. I use the 100
Hz filter of my MV62 level meter, which is a 200 kHz mechanical filter with
similar data as the old colins filter. 

For normal CW operation this filter normally is excellent, in case of a
case I can still use a 20 Hz DSP filter (build into my IC-746), but
normally this only improves the signal if there is really another station
near by.

I also have another level meter, a D2108 mad by Siemens. It has got a 20 Hz
IF filter, which is too narrow for normal CW. The next step, a 400 Hz
filter, again is too wide. 

So my recommendation for a normal CW LF Receiver is 80 to 100 Hz. For Slow
CW the program (either Spectrogram for 3 to 5 second dots or Spectran for
>20 second dots) does the job of a 0.00x Hz wide filter.

Talking about Spectran: IK1ODO, when and where do you begin your tests?


Best 73

Geri, DK8KW (W1KW)