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What steps do I follow using full duplex (FDX) on a 6600 to listen to my own TX signal in order to t

Bill OwensBill Owens Member ✭✭
Recently I learned that one can use full duplex in conjunction with two slices, one being the slice you would use to transmit/receive normally, and the other being the transverter input (without transverter) and set to receive only AND without any antenna. I know the transmit power has to be low so as not to damage the receiver. This setup is specified in the User Guide for SSDR, so apparently it is being done, but I can't find any specific steps showing how to go about implementing it. This technique is desired over just looking at the ALC, etc. or asking someone "how do I sound". Thank you for your response.


  • KF4HRKF4HR Member ✭✭
    edited October 2019
  • Bill OwensBill Owens Member ✭✭
    edited October 2019
    Thank you. I will check them out.

  • Mike-VA3MWMike-VA3MW FlexRadio Employee, Community Manager admin
    edited October 2019

    If the videos don't help, let us know and we can help you out.

    But, essentially:
    • 2 Slices same frequency 
    • RX on RXa (or b) 
    • TX on antenna for the band, or even better, dummy load
    • Reduce power to 5 watts or so
    • Turn on FDX
    • Turn down volume on TX slice and up on RX slice
    • Headphones are preferred as it is easier to hear yourself
    • TX focus on the slice with TX on the dummy load
    • Listen to yourself on the other slice in full duplex mode.  
    You can do this on all 6000 series radios.

  • Bill OwensBill Owens Member ✭✭
    edited October 2019
    Thanks Mike. Between the video's and your instructions, I should be able to implement the testing procedure.

  • Mark NS9NMark NS9N Member
    edited October 2019
    Hi Bill, although this works quite well, I find that if you just do a quick record into a dummy load then listen to the playback, you will get a much better representation on your xmit audio. The little red record button on the pan adaptor and the green arrow is all you need. Using this method I have significantly changed my microphone profile and now get outstanding reports. I have even switched back and forth on our local net and the validates what you hear in your recordings is what other will hear on the air. Thank you Flex for making this option so easy! 73s Mark
  • W2ECKW2ECK Member ✭✭
    edited March 4
    I'd really like to try FDX monitoring but want to make sure I fully understand how it works and ensure I don't damage my 6600. So to clarify for me, setting up for Tx. You can use a dummy load ( better than an antenna for the band ??) or select select XVTA or B even though you don't have a transverter installed. 
    1) So I guess even though you are transmitting into a dummy load there is enough of a signal be radiated to be received in the other slice??
    2) Transmitting into the slice with the XVTA albeit no transverter installed - don't understand how this is being received in the other slice- can someone explain?

    thanks & 73 Paul w2eck
  • Ken WellsKen Wells Community Manager admin
    edited October 2019
    In order to monitor your transmit audio for testing purposes...Set your transmit to the Transverter port (XVTR, XVTA, XVTB, depending upon what radio you are using).  That way you will not be sending a signal over the air.   Your listening slice should listen on ANT1, ANT2 or RXA or RXB.

    Even if you are sending to a dummy load on ANT1 or ANT2, You will likely have too much power output leaking internally to monitor the same frequency unless you keep it below a watt or two.

    The process works because you are listening to the slight bit of leakage from the transverter port to the antenna port you are listening with.  It only takes a few microvolts of signal to be received in your receiver.

  • W2ECKW2ECK Member ✭✭
    edited October 2019
    Ken - thanks - I now understand. Will give it a try.

    73 Paul
  • Andy - KU7TAndy - KU7T Member
    edited October 2019
    Does the transverter port need a load to be connected (antenna, dummy load)?  Sorry, I have no experience with transverters in case this is a dumb question...


  • Ken WellsKen Wells Community Manager admin
    edited October 2019
    The maximum power output to the transverter port is somewhere between 10 mW and 30mW, depending upon your radio.  I ran most of my tests with no termination (and no transverter).  But if you are concerned about having it properly terminated. you can get miniature 50 Ohm terminators that fit a BNC for a couple of bucks.

    BTW.  I also had QSO's about two miles away on 10 meters by connecting my Transverter output directly to my Log Periodic antenna at 38 Ft.

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