Hi Jan, I don't think the K3/100's -29 dB for TX IMD is all that far out of line with today's 100 watt class rig. In fact most 100 watt 13.8 volt rigs are a dB or two from this. I think the K3 QRP rig wasn't this good on bands above 17m @ higher power, but still measured -27 dB. Although it would be nice to have it much better (mid 30s or even in the 40s), even my Icom 7700 is was only measured @ -28dB with MRF150 final with 48 volts on them. Seems very rare for a current rig to be in the high -30s and -40s.
So I am not sure what the bench mark would be on TX IMD these days or if we could afford it? Question, can you hear IMD off the air or just the artifacts? As Wayne said earlier everything is a trade off. 73 de jay/w5jay.. ----- Original Message ----- From: "Jan Erik Holm" <sm2...@telia.com> Cc: <elecraft@mailman.qth.net> Sent: Sunday, January 25, 2009 11:53 PM Subject: [Elecraft] 6 Meters and TX IMD Elecraft K3 is sold as a "High Performance Radio", this is in print clearly stated on the web page. The 6m RX in K3 can not be called high performance. With a NF of above 10 and MDS as it is. The transmitter on SSB has so poor IMD that it can not be called high performance. ARRL and many others has measured poor TX IMD. I hear K3´s on the air every day with poor SSB TX IMD. People do have problems with PSK and other digital modes due to poor TX performance. IMO 6m is fixed with the preamp, no big issue anymore. However it should be stated in advertisement that for high performance on 6m K3 needs a preamp. Then we have the transmitter, what to do?? The problem has been swept under the carpet and it doesn´t go away by itself, it is stil there, under the carpet. 73 Jim SM2EKM ---------------------- Ron D'Eau Claire wrote: > I can't speak for the engineering or product decisions that went into > offering 6 meters with the K3, but for an excellent low-noise 6 meter > capability Elecraft does offer the XV50 transverter which is well > integrated > into the K3 and K2 rigs offering direct frequency readout, all of the > capabilities of the base K3 (or K2), and the 6 meter band becomes part of > the band selection just like the HF bands. > > The XV144, 222 and 432 round out the same capability, letting you cycle > through bands using the K2 or K3 bandswitch from 160 through 70 cm with > one > rig, and each of the VHF/UHF transverters has a low-noise high-performance > receive front end designed specifically for that band. > > As Wayne's often mentioned here, the advanced up-conversion design of the > K3 > is superior for HF but makes incorporating VHF a real challenge. Using an > XV > transverter specifically designed for each VHF band keeps the K3 (or K2) > operating as a tunable I.F. in the HF (28 MHz) range. > > Ron AC7AC > > > > -----Original Message----- > > On Sun, 25 Jan 2009 12:34:03 -0500 > "Phil LaMarche" <plama...@verizon.net> wrote: >> I purchased a used FT 100 just to monitor 6 while using the other bands > with >> the K3. Today there is a great opening. Signals are screaming from the > FT >> 100 and hardly heard on the K3 using an antenna switch. Guess I better > get >> a Preamp in line quickly. >> >> Phil >> >> >> Philip LaMarche >> LaMarche Enterprises, Inc. >> <http://www.instantgourmetspices.com/> www.instantgourmetspices.com >> >> www.w9dvm.com <http://www.w9dvm.com/> >> 800-395-7795 pin 02 >> 727-944-3226 >> FAX 727-937-8834 >> NASFT 30210 >> W9DVM > **************************************************************************** > ***** > > Phil, > > You're right about the 6mtr. band being practically deaf in the K3!!! I > did > order the 6m. preamp > because of > that short-coming! But you would have thought that the BOYZ @ Elecraft > would'nt have short-changed > 6m sensitivity as ALL THE OTHER BANDS HEAR WELL!!! > > Why build a quality rig if one-band is only added as a "after-thought"??? > > Jim/nn6ee > S/N 2406 > > > _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
