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T/R Relay noise with Antenna Tuner - 6600

KD8KKD8K Member ✭✭
Normally CW is silent, no relay noise at all. However, I noticed that when the internal Antenna tuner is active on the 6600 there is a T/R relay clicking when sending CW. It is a very noticeable difference with the tuner on and off. Is this normal, or is there a setting somewhere I have overlooked?


John KD8K


  • Steven WA8YSteven WA8Y Member ✭✭
    edited May 2019
    You must be using v2.4.9
  • KD8KKD8K Member ✭✭
    edited May 2019
    I'm currently using 3.0.19. I never used the tuner until recently, so I am not sure if it occurred on previous versions.

  • Joe N3HEEJoe N3HEE Member ✭✭
    edited May 2019
    QSK with ATU engaged is not supported unless using a separate receive antenna. This is documented in the 3.0.19 user manual. Where you using QSK?
  • KD8KKD8K Member ✭✭
    edited May 2019
    The QSK enunciator is displayed with the tuner activated on a single antenna, so I assumed it was supported. Apparently this is not the case. I would much prefer that the tuner stay inline for receive to allow for CW QSK, but it is what it is.


  • Joe N3HEEJoe N3HEE Member ✭✭
    edited May 2019
    Flex sites potential performance issues when using QSK with single antenna with ATU engaged. I agree this is undesirable but I’m afraid this is how iQSK works with Flex. I did find a workaround but not sure it will work in V3. Try to change to another band then back . That forces QSK to work with ATU on my 6600M running 2.49.
  • Tim K9WXTim K9WX Member ✭✭
    edited May 2019
    For those operating scenarios where I need to use the internal ATU I also don’t want to use QSK.  So, the limitation of QSK not being available for single antenna ATU operation is not an issue for me.  I can run the CW delay slider up high enough (typically around 175) to eliminate the annoying clicks from the T/R relay.

    However, this solution is not ideal in that I then bump into the problem documented at https://community.flexradio.com/flexradio/topics/missing-first-element-in-sidetone.  Missing the first element in the sidetone makes sending by hand a near impossibility.  I need to minimize the CW  delay in order to consistently hear the first sidetone element on a noisy band, and 175 is too high. 

    As I look at the release notes for V3 and V2.5 I don’t see any indication that the “missing first element in sidetone” issue has been addressed.  I have yet to upgrade from 2.4.9 and, regardless of which way I go, it appears I will need to continue to choose between listening to the T/R relay clicks or sometimes/often missing the first element in the sidetone.  This choice is one of those “rough edges” in SSDR that I hope can be addressed in the near future.

    Tim K9WX

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