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Elecraft K4

Discussion in 'Ham Radio Discussions' started by W6RZ, May 16, 2019.

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  1. K2XT

    K2XT Premium Subscriber QRZ Page

    Shame might work. "If you can't beat the IMD performance of a 6146 in a Collins 32S3 from around 1960 you still have work to do."
     
    N2EY likes this.
  2. N2EY

    N2EY Premium Subscriber QRZ Page

    You mean like this?:



    (Game Of Thrones reference)


    But you've got to define exactly what that means.

    And remember what a 32S-3 cost 55 years ago, in today's dollars. The response might be "what's it worth to you?"

    73 de Jim, N2EY
     
  3. WF4W

    WF4W Premium Subscriber QRZ Page

    i can appreciate the dual receive, multiple antenna ports, the HDMI, and built-in networking. I'd like to see what MORE it gives me over the IC-7610 or FTdx-101 to warrant the extraordinary price tag. . .
     
  4. W1VT

    W1VT Ham Member QRZ Page

    As reported in the November 2018 QST, a coupler returned too much signal to the 8000DLE, preventing the pre-distortion circuitry from functioning properly.
    Apache Labs chose to have QST publish results on the radio obtained by the ARRL, rather than waiting the indeterminate amount of time necessary to fix and retest
    the radio. As anyone familiar with repairing new technology knows, it is impossible to know how long that will take.
    The November 2018 QST also contains test results for the repaired radio.

    I think this is a predictable consequence of testing radios purchased on the open market, as opposed to doing reviews on prototypes provided by the manufacturers.
     
    Last edited: May 21, 2019
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  5. N2EY

    N2EY Premium Subscriber QRZ Page

    I did some perusing of ARRL "Product Reviews" (actually, "Recent Equipment") of the past.

    The earliest article I could find that showed HF SSB two-tone transmitter IMD test results with spectrum analyzer screenshot was November 1970, where the ARRL Lab reviewed the Allied A-2517 transceiver *. Before that, I couldn't find a review with a spectrum analyzer screenshot.

    So it's close to 50 years!

    And....the article points out the method used by ARRL, and how it gives results that are 6 dB better than obtained by other methods. Every article I found after that pointed out the difference.

    * The Allied A-2517 was a rebadged Trio/Kenwood TS-510, similar to how Henry Radio sold a rebadged Yaesu FT-200 as the Tempo One.

    73 de Jim, N2EY
     
    Last edited: May 21, 2019
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  6. KM1H

    KM1H Ham Member QRZ Page

    That performance didnt require a Collins price tag. All it took was a few cheap parts to get the 6146 finals to perform well. I suspect but havent followed up on it, that since the S Line and KWM2/2A were also sold to the military, embassies, and other gummint users in the USA and international facilities they were required to meet their specs and not for Hammy Hambone frequencies.

    Kenwood Hybrids also had superb non ARRL performance.


    All those tests are into a flat 50 Ohm dummy load and do not reflect the real world reactive loads unless a tuner is used. At least with tube finals that reactance can be tuned out and the lab IMD retained without any extra equipment needed....up to a point depending upon the tuning range of the pi networks used.
     
    Last edited: May 21, 2019
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  7. KJ4VTH

    KJ4VTH Ham Member QRZ Page

    You guys should be working for the radio companies instead of wasting your time on internet forums. :cool:
     
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  8. K2XT

    K2XT Premium Subscriber QRZ Page

    And the test equipment has changed but the results are still reported consistently so that comparisons are valid.
    I have no idea if there are software licensing restrictions that would permit other mfrs from doing what Anan did with the adaptive predistortion feature. But the Anans are certainly not priced out of the market because of their implementation. In fact just the opposite. For around $2700 you can get one of the most, if not the most, technologically advance rigs in the world, the 7000 model. (I know, I know, you have to have a powerful PC).
     
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  9. N2EY

    N2EY Premium Subscriber QRZ Page

    If that's the case, why haven't you written an article and gotten it published about how to improve the IMD performance of older rigs with 6146 finals? Or did I miss such an article?

    Sure - but - what were the specs of those times? And, given the chummy relationship of Collins and The Government back then, who is to say the specs weren't written to match what the S-line could do?

    The Product Reviews in QST for the TS-520, TS-530S, TS-820S and TS-830S show -32 dB, -28 dB, -39 dB and -32 dB dB third-order IMD, respectively (ARRL method). If that is "superb", then a lot of rigs of the era were....heck, the HW-101 tested at -30 dB using the ARRL method. The Yaesu FT-102 tested at -40 dB (ARRL method)!
     
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  10. N2EY

    N2EY Premium Subscriber QRZ Page

    Done by the ARRL method of testing.....
     
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