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EME with Flex 6600

I am considering the possibility of using my Flex 6600 for EME in the following configuration: .

  1. 2m 12+12 element Crossed Yagi.
  2. Dual RX transverter to go with my Flex 6600.
  3. 2 instances of WSJT-X/Q65 or MAP65/JT65/Q65.  

Then came the following message: WSJT-X does not do adaptive pol so running two instances has no advantage. Download MAP65 to do adaptive dual-pol reception. I've been told that Flex dual Rx are not coherent (locked in phase) so MAP65 will not work with it. I suggest you look at teh IQ+, which is a 2m dual-pol SDR. Just connect two LNA and a dual channel soundcard.

In response came the following message from Bill Somerville G4WJS of the WSJT-X team:

Hi Amos,

there are two aspects to adaptive polarization:

1) two I/Q data sources with stable clocks from 90 degree different polarized sources can be combined using DSP to extract signals at any desired polarization, that allows a search for decodes at different polarizations. MAP65 does this for 0, 45, and 90 degree relative to some arbitrary 0 degree source. Finer polarization resolution is not considered productive as the extra CPU resource has to be offset by the need for decoding within a deadline versus exponentially decreasing decoding gains for smaller polarization increments.

2) a system with synchronized I/Q data streams from 90 degree different polarized sources, if properly calibrated, allows MAP65 to display the absolute polarization of the decoded signals. This allows the best transmit polarization to be chosen to reply with, a significant advantage. The starting point for synchronized I/Q streams is that the I/Q detectors in the radios run from the same reference clock. Further to that the path delays through from aerial receiving elements to the decoding application must be either exactly equal or compensated for by a calibration tool and suitable adjustment (that could be a known signal polarized at 45 degree to the receiving aerials which would have equal strength to both polarizations, MAP65 has a calibration parameter to record the resulting offset and correct for it).

The I/Q+ is a specialized wide band dual I/Q detector with a common reference clock input (LO if you will), that can be used to obtain two exactly synchronized I/Q data streams which can then be fed to a 4-channel sound card like the LinkRF UADC4, which in turn is used for the input to MAP65. Rx frequency conversion would not be required for 2m as the IQ+ is specified for direct conversion between 40MHz and 900MHz, a pair of good quality LNAs in front of the IQ+ would be needed. Tx is another matter.

73 Bill G4WJS.

My questions:

  1. Does that mean that Flex 6600 can't be used as a part of a high capacity EME system?
  2. Please go into this information and tell what's right and wrong.

Amos 4X4MF


  • W4TMW
    W4TMW Member ✭✭


    Please give us some more basics about your setup;

    1) Please describe your 12 El antennas...... i.e. boom length and who's design or is it homebrew?

    2) what transmission line do you plan to use and how long?

    3) How much power do you plan to use?

    4) Will you be using a RX preamp at the antenna, if so, what N/F (noise figure) ?

    It's been a while since I ran any single antenna digital EME, all the items above are extremely important considerations.

    Tom, W4TMW

  • Amos Sobel
    Amos Sobel Member ✭✭


    My investigation of the EME capability of Flex 6600 centers now on MAP65 which is currently not compatible with Flex. Joe Taylor is now working on MAP65 v3.0. I am trying to find out if it is compatible with Flex or planning it for the future.

    I will let you know about my results.

    Amos Sobel 4X4MF

  • Amos Sobel
    Amos Sobel Member ✭✭


    I just got this from Joe Taylor:

    " MAP65 requires receiving hardware that can produce I/Q data at 96000 Hz sample rate. For adaptive polarization you need two independent channels of such information, and samples in the two channels must be synchronized. Flex receivers do not provide such data."

    1. Flex does provide:

    DAX IQ RX 1 (Flex Radio Systems DAX IQ), DAX IQ RX 2 (Flex Radio Systems DAX IQ), DAX IQ RX 3 (Flex Radio Systems DAX IQ), DAX IQ RX 4 (Flex Radio Systems DAX IQ)

    Which I did never use. What is it for?

    2.Does the 2 Flex Panadapters have any serial or other output?

    '3. Is there a way by which Flex 6600 can provide the 2x synchronized I/Q data streams at 96000 sample per second required by MAP65? This is the best way of doing EME contacts.

    Amos Sobel 4X4MF

  • JoeDeJesus
    JoeDeJesus Member
    Hello, Any luck or progress Flex and MAP65?
  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

    Not sure, but I did 2 EME UHF QSO's on my 6600 using JT65, a Q5 transverter, 80 watts and a 23 Element beam.

    What does MAP65 get you over the standard audio stream?

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