Flex-6700 External GPSDO Questions

KD0RC

How high do you have the output level on the GPSDO?  Check to see what the 6700 expects, then use GPSClockConfig to set the output close to that.  Kind of shooting in the dark at this point, but maybe this will do it...

73,
Len, KD0RC

Ed, K0KC

Len,

For my previous tests, I set the GPSDO drive at 16 mA which should give me +9.0 dBm output according to the GPSDO documentation. I use a 3 dB splitter, so the input to the 6700 should be +6.0 dBm. I understand that the 6700 specs are for +4.0 dBm minimum, so it should be ok.

I just changed the GPSDO drive to 32 mA which is supposed to give +10.3 dBm out minus the 3 dB loss from the splitter for an input of +7.3 dBm to the 6700. This is less than the 6700 spec of +15 dBm max.

I will let this setup run overnight to see if the increased output from the GPSDO solves the problem.

Thanks for your suggestion!

Ed, K0KC

Dwayne_AB6A

Ed, K0KC

Dwayne_AB6A

KD0RC

Great news, Ed! If it stays locked for a second day, I would say you have it solved. Len

Ed, K0KC

Ed, K0KC

Tim - W4TME

#3 may be RF overload, not RFI since the GPS antenna is an active antenna.  You may need additional physical separation to solve this issue.

Ed, K0KC

Final comment (really):

I solved the RFI problem today!!! It turns out that for some reason the 6 meter transmitter that caused the problem (IC-7700) was not connected to my single-point ground. I must have missed this connection when I rearranged the equipment some time ago. In any case, everything seems fine now.

Thanks again for all of the suggestions!

Ed, K0KC

KD0RC

YES!!  Glad you got that all figured out.  It is so frustrating when you carefully set everything up and still have problems.  Just shows that it can be the smallest thing that messes things up.

Len

Larry _ NY8T

 Resurecting this this thread to compare notes with 6700 owners that couldn't keep the external GPSDO's locked with the radio. After the v3.2.31 update I decided to hook my GPSDO back up and see if there was any improvement and so far its been a week and it has stayed locked. Previously it wouldn't go a full 24 hours without the 6700 loosing lock with the external GPSDO. I am interested to see if this is true for anyone else.

Ed, K0KC

As indicated in one of my old posts, my 6700 has stayed locked...no issues anymore.

Ed, K0KC

WX7Y

My 10MHz external GPS clock has also stayed locked on the 6700

Larry _ NY8T

Bret, since this last update or before the update has your external gpsdo stayed locked on your 6700?

Mike-VA3MW

@Ed, K0KC

I took a quick scan of this, but can you describe your Sky view and is the Flex GPS antenna near your other GPS antenna?

I know that sounds weird, but in years for using GPS's in commercial drones, I have seen 1 GPS cause another one to go out of lock due, what we think, is local oscillator interference.

Please describe the physical setup.

73

WX7Y

It would only stay locked on for 2 or at the most 3 days on the 6700, I have not powered down the radio to restart the 10MHz clock sink sense I installed version 3.2.31 when it first came out (KNOCK ON WOOD).

My FLEX 6600 always stayed locked at the exact same station just the 6700 would unlock even with the two radio's sitting side by side.

I do not use the built in FLEX GPS's in my radios.

Ed, K0KC

As indicated in one of my old posts, my 6700 has stayed locked...no issues anymore.

Ed, K0KC