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10 Mhz

I connected my 6500 to a gps receiver with 10Mhz output. I see the peak on 28 Mhz panadapter at 10 Mhz but how can I be sure that the 6500 is using the external 10 MHZ reference? I read a discussion where Tim explained to lokk at "clicks" during power on but I undestood 0%....
What does it means click? internal relay sound? Flash of power on led? Flash of alphanumeric display? Is possible to have a clear explanation?
If, for any reason, the 6500 loose the 10 Mhz ext reference, How can I be informed?

thanks for any help


  • WX7Y
    WX7Y Member ✭✭✭
    edited June 2020
    go to a WWV signal on the receiver and Zero Beat the carrier, Zoom in the Pan adapter so the band pass fills the screen if the radio is using the external 10MHz clock then the carrier should be right at 10.000.
    Then unplug the 10MHz clock and you will probably see it jump and not be exactly zero beat any longer on the WWV carrier.

    Plug the 10MHz source back in and you will notice it will NOT sink back to the external 10MHz Clock UNTIL you power down the radio and turn it back on.

    My radio will NOT stay sinked to the external clock more then a day or two which sucks because I leave my radio on all the time as a Radio Server.

    I have not tested this with Version 2 SmartSDR but I didn't see anything in the release notes so I dought it has been fixed or changed in operation.

    73's Bret

  • Stefano - W2WTZ
    edited July 2017
    Nice trick.... :) I will try later...
  • Peter K1PGV
    Peter K1PGV Member ✭✭
    edited June 2020
    >My radio will NOT stay sinked >to the external clock more then a day or two Really? That seems really odd. The external clock is just providing a frequency reference. How could the radio stop using it after period of time?? How do you re-sync it?? Have you told Flex about this? This doesn't sound right to me. Peter K1PGV
  • Martin AA6E
    Martin AA6E Member ✭✭✭
    edited January 2020
    I have also had reference selection problems. This is with GPSDO installed. With good sat lock in GPS, my 6500 drops sync and starts free running (as it seems) for a second before locking again. Check my video at https://youtu.be/UzhlkAokKAQ . Rig is unusable when this starts. It has gone back to Austin, where it's been sitting for 3 weeks now. (Hint to mgt.)
  • Al K0VM
    Al K0VM Member ✭✭✭
    edited November 2017
    Under the RX tab you can run calibrate with and with out the external reference..  With the External ref the off set should be very close to 0.  WIth the internal ref it is likely to be in the 100's of ppb.
    I have run on external refernce for years with NO reference drop outs or loss of sync.

    AL, K0VM
  • Stefano - W2WTZ
    edited July 2017
    I think that priority is to get informed if the radio is in synch or not. One year ago Tim wrote that an indication was on the wish list.
  • Tim - W4TME
    Tim - W4TME Administrator, FlexRadio Employee admin
    edited August 2017
    A few things

    1.) The radio only searches for a driver (reference) clock once at the time the radio boots.  It looks for an external 10 MHz source first, then it will look for the internal source (GPSDO or the OCXO or TCXO).

    2.) If the master XO cannot find a valid reference clock source, it will continue to search for it and this is indicated by a relay click every 2 seconds.

    3.) If the external source is used and that link drops, the radio will not fall back and start using an internal source.

    4.) There is no visual indication that the radio is using an external clock source.

    5.) To test it, connect your external reference and boot the radio.  Make sure it isn't clicking (item #2).
    Tune to WWV and you should have a straight line on the waterfall from the primary carrier.  Disconnect the external clock source and if you see the carrier line on the waterfall get wiggly, then it was using the external clock source.
  • Stefano - W2WTZ
    edited August 2017
    I tested the procedure and it works.Nevertheless If for any reason the 10 Mhz ref. signal is lost, how can I be informed? Don't you think that -in 2017-, counting the relais clicks is a little little little bit unsofisticated? 6500 has a multicolor led and a matrix display on the front, come on...

  • Tim - W4TME
    Tim - W4TME Administrator, FlexRadio Employee admin
    edited August 2017
    There is no visual feedback if the lock is lost.

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