GPSDO Not Detected by SmartSDR

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  • Updated 2 years ago
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I just installed a DOGPS module in a reconditioned Flex 6500 just purchased from the factory.  I'm using the latest SSDR -- 2.2.8.  The DOGPS unit had worked FB previously in another Flex radio.  When I say previously, I mean like two weeks ago.  However, SSDR says it's not present.  When I power down the 6500, I get the orange glow light, which I believe I read indicates that the radio knows the DOGPS is there and is keeping it powered while the rest of the radio is powered down.  So, why is SSDR not recognizing the DOGPS module?

The 6500 is hard wired to the LAN, and the computer (MS Surface Book Pro 2) is connected via WiFi.  SSDR has no trouble finding the radio, and I have no trouble connecting to it.  SSDR just doesn't see the DOGPS.

I have tried to a 6500 reset, but that has not solved the problem.  

What else should I try?

Thanks for any help anyone can give me.


Photo of  Carl Jón Denbow N8VZ

Carl Jón Denbow N8VZ

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Posted 2 years ago

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Photo of Chris DL5NAM

Chris DL5NAM

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do you activate GPSDO in menu?
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Carl Jón Denbow N8VZ

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Yes, if you mean click on "Install."  When I do that, it says "Not Found."  Thanks for the suggestion.
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try to remove the module, power the radio ON and OFF again and re-install it ...
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Tim - W4TME, Customer Experience Manager

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Carl, the bottom of the GPSDO module has a small surface contact connector that mates up to a connector on the PCB.  I suspect the connector is not properly aligned or something else may be causing a connection problem. 

I have taken 91% isopropyl alcohol and a q-tip and cleaned both connectors to make sure that any residue was removed. 

Also when installing the module, it is best not to tighten one side too tight before the other so that the module does not twist slightly that can cause the contact to become misaligned.
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Carl Jón Denbow N8VZ

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Thanks, Tim and Win.  I will try those suggestions and report back.  I guess I shouldn't have replaced all those darn screws before testing it out the first time.  It's just that I didn't expect any problem, since the module had worked FB in two other rigs.  I know what they say about ASS-U-ME! ;-)
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Carl Jón Denbow N8VZ

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Official Response
Well, guys, I followed both suggestions and the GPSDO is now recognized and is working FB.  There were a few anomalies during setup that I think I should report.  First, when I turned the rig back on after replacing the bottom cover (I had tested it first briefly with the cover off), it blinked orange for several minutes, then blinked blue for several more minutes (much longer than usual) before turning solid blue.  In fact, it did not turn solid blue until I ran SSDR, and viewed the GPS setup window.  I did not actually click install or anything.  It reported right away that "GPS is active" and was displaying the correct Grid Square, altitude, etc.  

A few details on my work: 1. I actually used a very small dab of DeoxIT rather than alcohol; 2. When I first turned the rig on for my bottom-cover-off-test I had the 6500 upside down, it would go through the calibration routine and then automatically shut down. I did this several times, always with the same result.  It would not actually boot up.  I then decided to put it right-side up, still with the bottom cover off, and voila it booted OK.  Is this standard behavior?  Does it have a sensing mechanism for its position?  

Thanks, again, for the suggestions! 
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Martin Ewing AA6E

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You're not supposed to get a blue light (or flashing blue) unless SSDR is running and connected to the radio, IMO.  Otherwise, you get orange or orange flashing.

I had considerable trouble with my GPSDO, which I finally traced to that 10-pin gold connector.  It seems to be awfully sensitive to any insult.  In my case, it appeared that one or more pins were slightly elevated or depressed.  I needed a powerful magnifier to see the problem.  Some very gentle tweaking brought them into alignment, and I've been OK since then.  This connector system is not exactly robust!

I would worry about de-ox, which might leave a residue. (With gold contacts, oxidation is not a problem!) Isopropyl alcohol is probably a better bet.

I also note that my GPSDO (with supplied antenna) does not seem to be nearly as sensitive as my Nexus 5X phone GPS.  That may be because it's harder to sync an oscillator than just to get time and position -- I don't know.  Anyway, I had to move the antenna out of doors and give it a large unobstructed sky view to get reliable sync, while my '5X worked fine inside the house.

If you're having problems running upside down (and there's no overheating), that suggests the GPSDO to chassis connection is not reliable yet.  You really want it to work solidly, because over time (on/off thermal cycles), the connector pins are likely to develop more contact problems.  At least, that seemed to happen to me.

73 Martin AA6E