K3: New (Jan 2009) ARRL review
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K3: New (Jan 2009) ARRL review
 
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For those ARRL members.......I've just stumbled upon the ARRL's follow-up review of the K3 on their website. Now, back to read the pdf....
Regards Paul M0CVX ex-AC5NO ----------------------------------------- Email sent from www.virginmedia.com/email Virus-checked using McAfee(R) Software and scanned for spam _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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That is the most perfect ARRL review I can recall having ever seen. Congratulations, Elecraft and pour a glass of champagne for everyone. You deserve it.
Knut - AB2TC K3 #82
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According to the review, the radio is nearly perfect. Very strong performance nearly everywhere.
There were only two sets of numbers that could raise questions. The TX 3rd order IMD performance was not that good (29db) but it was on the worst band. Not sure the testing was before or after the firmware changes to decrease TX IMD. W8JI praised K3's low SSB IMD. The second one was a mediocre performance of the 1.8 filter (see table below). It had worse close IMD than the 2.7 filter, in some cases by 20db! On the other hand, everyone in this group praises the 1.8 filter so perhaps the filter is still doing something useful. Also perhaps the latest 1.8 filters were improved. Third Order Intermodulation Dynamic Range (dB) at MDS (preamp off, 14 MHz) Spacing (kHz) Roofing Filter (Hz) above/below 2800 2700 1800 500 400 20 104/104 105/106 101/98 104/104 105/106 5 105/103 96/106 90/84 102/101 106/105 2 99/100 90/89 74/82 90/90 106/103 1 94/81 89/79 72/81 87/82 99/99 昀� |
RE: K3: New (Jan 2009) ARRL review
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> The second one was a mediocre performance of the 1.8 filter > (see table below). It had worse close IMD than the 2.7 > filter, in some cases by 20db! Careful reading of the review will reveal that the particular 1.8 KHz filter was probably defective. Elecraft run much higher signal levels in the first IF filter than other radios. That higher signal level can cause filter generated IMD if the crystals are not absolutely clean. Elecraft (and INRAD) are working on improved testing procedures to weed out those filters that are insufficient to handle the signals levels in the K3 (and divert them to use with Yaesu transceivers <G>). 73, ... Joe, W4TV > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Ignacy > Sent: Tuesday, November 25, 2008 4:20 PM > To: [hidden email] > Subject: Re: [Elecraft] K3: New (Jan 2009) ARRL review > > > > According to the review, the radio is nearly perfect. Very > strong performance nearly everywhere. > > There were only two sets of numbers that could raise questions. > > The TX 3rd order IMD performance was not that good (29db) but > it was on the worst band. Not sure the testing was before or > after the firmware changes to decrease TX IMD. W8JI praised > K3's low SSB IMD. > > The second one was a mediocre performance of the 1.8 filter > (see table below). It had worse close IMD than the 2.7 > filter, in some cases by 20db! On the other hand, everyone in > this group praises the 1.8 filter so perhaps the filter is > still doing something useful. Also perhaps the latest 1.8 > filters were improved. > > > Third Order Intermodulation Dynamic Range (dB) at MDS > (preamp off, 14 MHz) > Spacing (kHz) Roofing Filter (Hz) > above/below > 2800 2700 1800 500 > 400 > 20 104/104 105/106 101/98 104/104 > 105/106 > 5 105/103 96/106 90/84 102/101 106/105 > 2 99/100 90/89 74/82 90/90 106/103 > 1 94/81 89/79 72/81 87/82 99/99 > 昀� > > -- > View this message in context: > http://n2.nabble.com/K3%3A-New-%28Jan-2009%29-ARRL-review-tp15 Sent from the Elecraft mailing list archive at Nabble.com. _______________________________________________ Elecraft mailing list Post to: [hidden email] 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: [hidden email] 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 |
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> Careful reading of the review will reveal that the particular
> 1.8 KHz filter was probably defective. Elecraft run much > higher signal levels in the first IF filter than other radios. > That higher signal level can cause filter generated IMD if the > crystals are not absolutely clean. I've had two sets of filters (2x 2.1kHz and 2x 1.8kHz) and all four filters showed more or less similar dynamic performance to what the ARRL has seen. My filter setup is as follows: FM, 2700, 2100, 1800, 400 in the main RX and in the KRX3 6000, 2700, 2100, 1800, 400. I agree with you about the possible cause and I do know that Elecraft has been working hard on improving this, but all four of these filters did not prove to be terribly detrimental in any of the shortwave SSB contests my K3 has been used in or during the pile ups when it was with us on the Faeroe Islands (OY). To use German expression: Lets leave the church in the village. In other words, there is no need for storm in a tea glass. While the dynamic range is not as good as one might want, these filters are still very good for fishing out a weak one, stuck between two big guns. vy 73 de toby _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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