how do you calculate... I want to work more 6m signals and need to know the testing method. If signals are that better then I need to add the external unit.
Bill K9YEQ -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of James Duffey Sent: Friday, April 02, 2010 4:54 PM To: [email protected] 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:[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
