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Flex 6500 6 meter receive improvements in V2 software?

KA9CFD
KA9CFD Member ✭✭
edited July 2019 in SmartSDR for Windows
I would like to know if there will be any receiver improvements for the Flex 6500 in the version 2 software. Specifically receive sensitivity for 6 meters. 

Thanks, 
Jay KA9CFD

Answers

  • Dick Hale
    Dick Hale Member
    edited July 2017
    Me too!, but I don't think it's software...(;(
  • Mike W8MM
    Mike W8MM Member ✭✭
    edited July 2019
    Wow, ... I'm very envious if your location is quiet enough on 6 meters to possibly notice better sensitivity.

    Put a 50-Ohm load on the rx loop input corresponding to the same antenna as you have for 6 meters, then alternately select the antenna or the dummy load.  If you can see 6 or 7 dB of "antenna noise", you'll be hard pressed to notice any real-world improvement from lower noise figure.

    If you can see 10-13 dB (or more) of "antenna noise", it's theoretically impossible to notice the faintest difference.

    Do the experiment and tell us what happened.
  • Wim
    Wim Member ✭✭
    edited July 2017
    and it's better to put a preamp close to your yagi, then you compensate for all the coax loss
  • Mike W8MM
    Mike W8MM Member ✭✭
    edited July 2019
    A pre-amp only works if there is a real reason to employ one. If one is using the +30 dB built-in pre-amp gain setting on 6 meters, there is only the very slimmest chance that an external pre-amp is actually useful. If one refuses to do the antenna-vs-50-Ohm-load comparison, one is giving in to superstition instead of science. YMMV. "Antenna noise" ratio to a 50-ohm termination is the only proper way to decide.

    Superstition is a cruel master.
  • George KF2T
    George KF2T Member ✭✭✭
    edited February 2019
    Mike has a point. In all but a very small subset of locations, local noise will be the limiting factor for detecting weak signals. On 6 meters and below, the best results will come from reducing that local noise, rather than trying any more gain stages. Howard, KY6LA, presented a great tutorial on noise reduction some time back.

    Let me tell you, aggressive noise reduction is the way to go. And by that I mean dealing with the sources directly. Noise blankers and such are good (sometimes very good) tools, but nothing compares to shutting down the sources. You'll gain far more S/N that way.

    Above 6m, Wim is spot on about the preamp at the antenna. Even there, though, you may need to take aggressive steps on source noise reduction, or the extra gain is for naught. Each installation will be different.

    Good luck!
  • KA9CFD
    KA9CFD Member ✭✭
    edited July 2017
    The Flex 6500 built in preamp is 20 db, not 30 like the 6700. And it is a must use otherwise the radio would be deaf. I have worked 52 EU contacts in the log for this sporadic e season, all of it digital.
  • KY6LA_Howard
    KY6LA_Howard Member ✭✭✭
    edited July 2017
    In V2.0 the Flex 6700 Preamp is upgraded in software to +40dB so that is a definite improvement for 6M
  • KY6LA_Howard
    KY6LA_Howard Member ✭✭✭
    edited July 2017
    The above link is toy aper on noise mitigation
  • Tim - W4TME
    Tim - W4TME Administrator, FlexRadio Employee admin
    edited July 2017
    The answer to the original question, is there are no specific program changes specific to 6m improvements on 6m.

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