> But these "artifacts", at least in my observation, are only > present when a signal is present. If they are there when only > noise is being received, they are below the extremely low out > of band noise level.
I see 7.8 and 12 KHz products clearly at about 10 dB above the stopband noise with no signal present. They get much stronger with signals present and additional products appear. Even though the maximum level is still 60 dB below the listening level, they are still clearly above the "masking" level and they will be audible to someone with normal hearing with "full range" headphones and/or speaker. 73, ... Joe, W4TV > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Julian, G4ILO > Sent: Saturday, January 09, 2010 5:11 AM > To: [email protected] > Subject: Re: [Elecraft] RX Test (long) > > > > > > Joe Subich, W4TV-4 wrote: > > > > > > Here is the genesis of the complaint that the K3 is more > > fatiguing than other receivers. The out of band noise > > (noise above 5 KHz) in the K3 is, as you say, at least 60 dB > > below the peak audio level (actually, I measure it at more > > than 90dB down above 5 KHz). However, the stopband also has > > many leakage products (DAC artifacts) in the stopband some > > of which are as much as 50 dB ABOVE the noise floor. > > > > While these products are well below the desired audio in the > > passband, they are "in the clear" as far a local noise. > > This requires the ear/brain system to subconsciously work > > to reject (filter) the undesired discrete frequency products. > > > > > > But these "artifacts", at least in my observation, are only > present when a signal is present. If they are there when only > noise is being received, they are below the extremely low out > of band noise level. Therefore, whilst I can see that they > could contribute to unpleasant or tiring sounding audio for > those blessed with acute hearing, I can't see that they would > result in the receiver sounding noisy. > > ----- > Julian, G4ILO. K2 #392 K3 #222. > * G4ILO's Shack - http://www.g4ilo.com > * KComm - http://www.g4ilo.com/kcomm.html > * KTune - http://www.g4ilo.com/ktune.html > > -- > View this message in context: > http://n2.nabble.com/RX-Test-long-tp4275854p4277032.html > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > 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 ______________________________________________________________ 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
