K6KR wrote: >I notice a definite qualitative change as the narrower filters switch in. It sounds quieter, and it seems like the volume is being turned down. I think I'm responding to the reduced low and high frequency components that are supposed to be cut off. The DSP-related changes seem more gradual.
Dick made some very good points about using the K3Utility to enable different filters and about the need to set gain correctly for each filter. Here's a simple test that may surprise you: 1. Disable all filters but your 2.7 or 2.8 for CW (using Dick's K3Utility). 2. SLOWLY rotate WIDTH from 1.5 to 0.05. 3. Note how the character of the noise changes. I find abrupt changes in noise character between some DSP settings...and this is *not* due to the roofing filter since that is held constant at 2.7k. The abrupt changes I hear using a 350 Hz CW pitch setting are: 1.1 - 1.0 0.90-0.85 0.70-0.65 0.50-0.45 0.30-0.25 0.20-0.15 Do you see a pattern in the above? I hear something which repeats almost every 0.20 increment...(and I bet Lyle can explain why). I recall seeing this on Spectrogram when I was closely looking at DSP BWs shortly after I got my unit. We did discover some serious offset problems at the low end (which Lyle has since fixed), but I recall the DSP BW changes were never exactly linear as you reduced BW. This is not a particular concern to me but curious nevertheless. 73, Bill -- View this message in context: http://www.nabble.com/Hearing-the-effect-of-narrower-roofing-filter-tp18329150p18342146.html Sent from the Elecraft mailing list archive at Nabble.com. _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
