[RFI] Noise Canceller vs DSP filter

Pete Smith n4zr@contesting.com
Fri, 18 Oct 2002 16:43:16 -0400

At 12:29 PM 10/18/02 -0700, John Geiger wrote:
>Has anyone had any luck using different DSP filters to
>remove power line noise-like the TImewave 599+ or
>anything like that.  What works, what doesn't?  ANd
>should I just expect a S5 noise level on the low bands
>due to atmospheric noise?  It seems to me I don't
>remember it being that bad in the past.

I have had varying degrees of luck with the DSP in my Mark 5, 
night-to-night, and experimented with an outboard audio DSP box on my 
previous radio but sent it back.  The noise canceller depends on the noise 
being a single source, because it relies on phasing and cancellation.

I'm a little suspicious that your problem is line noise, at least on the 
low bands.  You should be able to hear the 60-Hz component, if it is, 
particularly if you switch your radio to AM mode.

S5 on 80 would be a pretty quiet night here.  Right now, in mid-afternoon, 
my 80-meter antenna is giving me about S4-5 on the Mark 5, with no audible 

73, Pete N4ZR
Sometimes a tower is just a tower