Agreed!!! The preamp creates the amplification of incoming noise. Adding an attenuator after the preamp makes little sense.
I do not use the preamp unless the noise floor is low. I use the ATT when the noise is high without the Preamp. Really helps pull sigs in. Forget the S meter readings other than to help you decide on how to use the ATT and Preamp settings.... This helps the dynamic range. I would rather listen to a clean S7 signal than an S9 + without clarity. Hope that makes sense. Bill K9YEQ -----Original Message----- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of ab2tc Sent: Wednesday, August 11, 2010 3:50 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] K3: PRE/ATT Bug or feature? Oof. Having the attenuator and preamp on at the same time is completely nonsensical. The gain of the preamp is ~11 dB and the loss of the attenuator is ~10dB so they almost completely cancel each other out gainwise. But *all* the noise from the preamp will be added, so your noise floor will be significantly raised and there is *no* advantage gained. The total dynamic range will be reduced by at least the increase in the noise floor (that's assuming that the preamp is completely distortion free). AB2TC - Knut The Smiths wrote: > > > I find it to be much better in some circumstances. I find that the > noise floor is actually reduced, not brought up by the 2dB that would > be expected. This is very similar to when I adjust the RF Gain down > to about > 3 o'clock. Yet it works much faster because I can simply push the > button on and off when I need it. > > <snip> > -- View this message in context: http://elecraft.365791.n2.nabble.com/K3-PRE-ATT-Bug-or-feature-tp5392799p541 3907.html Sent from the [K3] 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:Elecraft@mailman.qth.net 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:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
