> The Elecraft external preamp with 0.7 dB noise figure and 18 > dB gain helps a lot: > > K3 with PR6 external preamp > > preamp on 0.9 dB > > And the preamp is pretty robust to strong signals. >
Is this calculated with both preamplifiers on (cascaded) or with the PR-6 only? 73, ... Joe, W4TV > -----Original Message----- > From: elecraft-boun...@mailman.qth.net > [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of James Duffey > Sent: Friday, April 02, 2010 5:54 PM > To: elecraft@mailman.qth.net > Cc: James Duffey > Subject: Re: [Elecraft] K3 - Performance on 6M? > > > No need to speculate on the 6M K3 NF, we can calculate it. > Computing the K3 noise figure from the minimum discernable > signal (MDS) gives > > preamp off 18 dB (K3/100 test) to 20 dB (K3/10 test) > > preamp on 12 dB (Same in both tests) > > compare these to other 6M rigs out there: > > IC-551D > preamp on 6dB > > internal rf amplifier not switchable > > DEM 50-28CK transverter with TS-850S IF > > preamp on 2.1 dB > > > FT736R > preamp on 5.7 dB > > TS2000 > > preamp off 20 dB > > preamp on 5 dB > > IC756 Pro III > > preamp off 15 dB > > preamp on 5 dB > > FT2000 > preamp off 26 dB > > preamp on 8 dB > > So the K3 is pretty deaf on 6M and yes, that is a result of > the design emphasis on HF strong signal handling capability. > The Elecraft external preamp with 0.7 dB noise figure and 18 > dB gain helps a lot: > > K3 with PR6 external preamp > > preamp on 0.9 dB > > And the preamp is pretty robust to strong signals. > > For terrestrial signals in a quiet rural area, a noise figure > of 4dB or less is probably adequate. For EME, you want less. > For urban and suburban areas, the noise is often high and > many people, unfortunately won't notice the inadequacy of the > K3's front end on 6M. - Duffey > -- > James Duffey KK6MC > DM65tc > Cedar Crest NM > > > > > > > ______________________________________________________________ > 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
