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FLex 6600 "SCU" vs "Independant" receivers.

wb7ond Member ✭✭
edited November 2019 in FLEX-6000 Signature Series
As I understand, the Flex 6700 has two SCUs from which you spawn slice receivers tied to each SCU.   The Flex 6600 spec sheet shows an "independent" receiver number.  The number of SCUs seem to determine whether you can do full duplex with 2M/440 down convertors.   I am trying to work out the number of SCUs on the Flex 6600, and whether full duplex satellite work is possible when fitted with downconvertors.   Can anyone shed light on the number of SCU for the Flex 6600?  Thanks 


  • Richard Hubbard
    edited November 2019
    The specs for the 6600 are exactly the same as the 6700, except for the number of slices 4 vs 8. The 6600 has two independent SCU's and two independent Transverter ports, and is Full Duplex.

    Receiver Specifications 6600
    • Receiver Architecture: Direct Digital Sampling
    • Spectral Capture Units (digitizers): Two (2)
    • Maximum Slice Receivers: Four (4)
    • ADC Resolution: 16-bits
    • ADC Sampling Rate: 245.76 Msps
    • Wideband Frequency Coverage: 30 kHz - 54 MHz
    • DAX IQ Channels / Bandwidth Per Channel: Four (4)
    • DAX Audio Channels: Four (4)
    • Amateur Band Preselector Coverage: 7th order on contest bands; 3rd order on remaining
    • 1/2 kHz Reciprocal Mixing Dynamic Range (RMDR): 110/116 dB
    Spectrum/Waterfall Display Specifications
    • Maximum High Resolution Spectrum Displays: Four (4)
    • Panadapter Bandwidth: 1.2 kHz - 14 MHz
    • Spectrum Dynamic Range (max zoom): > 155 dB
    • Spectrum Resolution Bandwidth (min): 1.6 Hz
    • Integrated Touch Panel Display Size (diagonal)1: 8" (20.3 cm)
    • Integrated Display Resolution1: 1920x1200
    • External Display Resolution/Connection1: 1920x1200/HDMI
    Transmitter Specifications
    • Transmitter Architecture: Direct Digital Up-conversion
    • Modulation System: Digital Low Power at Carrier Frequency
    • RF Output Power: 1-100W nominal SSB, CW, FM, RTTY, Digital; 1-25W nominal AM
    • Amateur Band Coverage at Rated Power Output: 160m – 6m
    • Transverter IF Output Power: +0 dBm Typical; +10 dBm max
    • Transverter IF Frequency Coverage: 100 kHz - 54 MHz
    • DAX Transmit Channel: Yes
    • Harmonic Suppression: < -60 dBc typical
    • Transmit Bandwidth: Default 100-2900 Hz (Variable 50-10000 Hz)
    • Microphone Connector: Pseudo Balanced 1/8" TRS
    • Microphone Impedance: 600 Ohms Nominal (200-10kΩ)
    Integrated Antenna Tuner Specifications
    • Matching Range 80m - 10m: Optional, 8.3 Ohms - 300 Ohms
    • Matching Range 160 and 6m: Optional, 16.7 Ohms - 150 Ohms
    General Specifications
    • USB 2.0 Ports (peripheral control): Two (2)
    • Internal 10 MHz Reference Clock Stability: 0.5ppm TCXO (0-50C)
    • Emission Modes: USB, LSB, CW, RTTY2, AM, Synchronous AM, FM, NFM, DFM, FreeDV2
    • Frequency Resolution: 1 Hz min.
    • Antenna Connectors: SO-239x2, BNC XVTRx2, BNC RX-INx2
    • Antenna Impedance (w/o tuner): 50 Ohm Unbalanced
    • Power Supply Requirements: +13.8V DC nominal ±15%
    • Current Drain (Receive/Transmit Max): 2.0A / 23A @ 13.8V
    • Height: 6.74" (17.1 cm) with feet
    • Width: 14.0" (35. cm)
    • Depth: 13.25" (33.7 cm)
    • Operating Temperature: 0 to +50 degrees C; +32 to +122 degrees F
    • GPS Disciplined Oscillator; 5x10-12 over 24 hours
    • MARS/CAP Coverage Filter Bank
    • ThumbDV module for D-Star mode

    Specifications subject to change without notice.
    1FLEX-6600M model.
    2RTTY and other digital modes requires 3rd party software over DAX channels.

  • Marc Lalonde
    Marc Lalonde Member ✭✭
    edited November 2019
    i almost sure it have 2 SCU  ,since  "Simultaneous Receive on Two Antennas (e.g. 20m & 6m)"
  • Richard Hubbard
    edited May 2017
    Sorry I meant to say the specs are almost the same.
  • Richard Hubbard
    edited January 2019
    I am hoping to use the 6600 with Khune transverters for satellite work, it looks like it can be done from the specs, and within the software.
  • Ria
    Ria Member ✭✭
    edited May 2017
    They are not exactly the same. From what I gather they are using different internals and the 6700 does 2 meters as well. Also the 6600 has contest grade preselectors and the 6700 does not. The 6700 also has an OCXO instead of a TCXO. 
  • Richard Hubbard
    edited May 2017
    Yes your right, not exactly the same; do you think the 6600 as is currently on paper gives better value for money than the 6700? Do you think that a replacement for the 6700 is around the corner, given the specs of the 6600?

    Best regards,

    Richard Hubbard.
  • Ria
    Ria Member ✭✭
    edited May 2017
    If you need only 4 slices and want to do SO2R you're good to go with the 6600.

    Receiver specs are so high among these models and all of the top on Rob Sherwood's list that it makes little difference which one you get from that list. The 6600 is lower priced but to me these are the significant differences.

    4 slices/panadapters vs 8 - for some of us it matters, eg cw skimmer on 4 bands at once while using other slices/panadapters to rag chew or work dx. For average users it really does not.

    2 meter capability - only really matters if you use 2m and higher. I say higher because transverters using 28MHz IF will be more limited vs ones that use 144MHz IF.

    Contest grade preselectors - matters if you're in a SO2R environment or close by other very strong signals. Matters less if you use external bandpass filters (switchable, individual band or stubs). You can also add them via the rx loop on the 6700. However, the 6600 offers a cleaner solution.

    Mic and headphone jacks - 6700 has 8 pin foster and 1/4" jacks. 6600 switches to cheaper 1/8" jacks (IMO that is a downgrade). 

    Not sure if the 6600 uses a TCXO or an OCXO. 6700 uses an OCXO.

    MARS is extra on the 6700 as the filters are now an option instead of being standard.

    I have no idea about replacements for the 6700. Flex keeps that info very much under wraps. It wouldn't surprise me if they bring out something next year. I kind of doubt it would have more than 8 slices as most people find that excess to their needs. 

  • wb7ond
    wb7ond Member ✭✭
    edited November 2019
    Thanks for the good info.  I was hoping that the 6600 had two SCU.  If I don't take a bad beating on the 6500 trade up, this may be a good backdoor to the top of the line 6700.  The 6600 seems almost 1/2 price of the 6700 with two scu, and top of the line preselector/filters.  I think that the 6600 is the hidden value here.  I don't need 2M built in, rather have it at the antenna along with the 440.  Just have to be patient.  Again thanks for the great response, I've learned some things.  
  • Richard Hubbard
    edited May 2017
    Thank's very much Ria, much appreciated.


    Richard Hubbard.
  • Ria
    Ria Member ✭✭
    edited May 2017
    It does.

  • Ria
    Ria Member ✭✭
    edited May 2017
    It was mentioned that the 6600 may have slightly better receiver performance than even the 6700 but this has to be confirmed through lab testing. 
  • wb7ond
    wb7ond Member ✭✭
    edited May 2017
    One can only hope, but only the spec is "gospel" for now.   Flex must have incorporated some improved semiconductors (FPGA??) to get the price down where it is now.  I for one am excited to see this radio come the fall...  
  • Michael Aust
    Michael Aust Member ✭✭
    edited May 2017
    Must be Dual in one IC Package 
  • Ria
    Ria Member ✭✭
    edited May 2017
    They said something along that line. Maybe not the FPGA but something else. 
  • Marc Lalonde
    Marc Lalonde Member ✭✭
    edited May 2017
    i bet it may now use "video card" GPU instead of Davinci DSP  
    some of Nvidia chip have 256 Core whit really nice price compared to a FPGA / DSP

    HPSDR guy already play whit that for some time now  (jetson TK1)
  • Tim - W4TME
    Tim - W4TME Administrator, FlexRadio Employee admin
    edited May 2017
    "i bet it may now use "video card" GPU instead of Davinci DSP  some of Nvidia chip have 256 Core whit really nice price compared to a FPGA / DSP"

    I would not make that bet ;-)

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