If you have lots of atmospheric noise, you may have too much gain in your revive chain, and should maybe consider switching off the preamp/switching on the attenuator.
There is also the "NR" noise reduction feature which may be useful. However on CW I find that narrowing the PBT bandwidth cuts out a lot of the band noise. As someone else stated, a roofing filter is not going to help you with this sort of problem; a roofing filter is to protect against strong stations on nearby frequencies so you don't get problems like AGC pumping and undesired mixing products. 73, Matt VK2RQ > On 25 Mar 2015, at 1:49 pm, Fred Jensen <[email protected]> wrote: > > Joshua, Probably not. The ultimate BW of your receiver is set by the DSP > and noise power is "sort of" proportional to BW. The purpose of the roofing > filters is to protect the ADC sampler at the head end of the DSP from very > strong signals that could drive it to saturation. > > Noise, other than atmospheric and galactic, needs to be attacked at the > source. Like getting rid of your switching wall warts and power supplies. > So long as the atmospheric noise is not saturating the ADC, reducing the DSP > BW is the only really effective way to reduce it's impact, and that's a lot > easier on CW than on SSB. Different roofing filters are not likely to make > much difference at all unless they're more narrow than your DSP setting. > >> On 3/24/2015 7:24 PM, Joshua Gould wrote: >> All, >> >> Would the roofing filters help reduce atmospheric noise? I'm having a heck >> of a time hearing anything over the S5 noise levels that I seem to be >> dealing with of late. But at least it's better than the S9 noise I was >> getting from switching power supplies under my desk... >> >> >> 72, >> Joshua Gould >> K8WXA >> EM89pn > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
