Flex 6500 GPSDO won't ock

K3DCW

I have a Flex 6500 with the GPSDO installed. It was working just fine with solid lock until last weekend when I powered it down for some storms.  Upon restart, the GPSDO detects the sats (9 tracked of 12 visible as I type),the time is correct as are the Latitude/Longitude, but the Status never changes from "Locking" and the blue light keeps flashing on the front of the rig.  I tried switching antennas and got the exact same result; near-instant detection of the birds, but no lock. 

I'm running v1.9.9.170 SSDR and v1.9.9.86 hardware firmware. 




Any ideas?

EA4GLI

The antenna that comes from Flex is an indoor antena that its supposed to be attached to a window on the inside with the supplied double sided tape.

I messed up and placed mine outside, water got inside the antenna and the GPSDO stopped getting a lock on sats.

I took the antenna apart and found water inside. I dried it, let it sit for a couplke of days and connected it again and was getting slightly better performance but not a lot of stability. So I went ahead and order a GPS outdoor antenna from ebay for $10.

It has been working great. I will look for the model I got and will post here.

EA4GLI

Here you go

http://www.ebay.com/itm/External-Amplified-tomtom-GPS-Antenna-for-GlobalSat-AT-65-SMA-28dbi-high-****...

I liked the fact that it came with 5m of coaxial allowing for many placement options.

You can find them cheaper if you go for 3m of coaxial.

http://www.ebay.com/itm/SMA-Male-Plug-connector-Car-GPS-Navigation-External-Antenna-RG174-3M-9-ft-ca...

EA4GLI

I re-read your post and see that you have tried with another antenna so you might have a different issue, but I was having the same problem (blue blinking, no lock) and mine was water ingress in the gps antenna.

K3DCW

I've tried two different antennas; the one from Flex and another small GPS (waterproof, outdoor) antenna that I ordered from Amazon. Neither have been outside; rather they sit in the window sill and have an excellent view of the sky.  

I have been using the Amazon antenna for several months now;  it used to lock just fine, usually within just a few minutes, but suddenly it has been unable to lock ever since I restarted the computer. I've been trying now for nearly 72 hours.

I have also restarted the 6500 a couple of times to try and get it to lock with no change. 

Bill -VA3WTB

72 hours and counting, open a help ticket.

EA4GLI

Did you uninstall GPS and reinstalled from the setup window?

K3DCW

Yes, I tried that too.  

EA4GLI

All I can think of is a bad connection on the coaxial SMA at the Flex radio. Look and make sure you have not pull the coaxial or that there is something on the way of the middle pin.

K3DCW

I've ordered another antenna, just in case.  Should be here tomorrow.  I'll take a look at everything again then. In the mean time, flash flash flash goes the blue light. 

George - AB4FH

Dave,
I, too, notice strange behavior of the GPSDO on my 6700 with the latest SSDR.  When the Flex is turned off, it seems to power down the GPSDO because when I turn the unit on the next day, it has
to relocate the GPS satellites and relock.  This takes about 10 minutes.  

It did not do this prior to version 1.99.

Sergey R5AU

Agreed, same things here with F6700 GPSDO - locking time up to 10-15 min, extremely stay long in Holdover state

Wayne VK4ACN

I use my flex gps antenna outside, but put it in a piece of pvc plumbing pipe and sealed it with a hole for the coax, works well attached to the side of the house

Jay Nation

I seem to having GPSDO problems too. Didn't notice them until this morning, I've been out of the shack since last Friday. I haven't made any changes to the GPS antenna other than reseating the SMA connector. My 6500 does seem to be stuck in holdover, When that problem occurred in the past it's always resolved itself automagically within a day or so. I guess you can add me to the list of people reporting this problem. WhenIf the trouble clears I'll report it here. Meanwhile I'll watch this thread for a solution. Reverting to SmartSDR v1.9.7 hasn't helped, I may try reverting to v1.8.4, but I'd prefer to stop trying anymore shotgun troubleshooting. The GPSDO was working fine last week. 

I'm now going to try SmartSDR v1.9.13 since it just became available.

 SDRgadgets

73, Jay - NO5J

Jon_KF2E

1.9.13? Beta?

Jon...kf2e

K3DCW

No, it was just announced. 

EA4GLI

GPSDO has not failed on me with none of the versions.
It is working OK now with 1.9.13 the one just issued a few minutes ago.

Jay Nation

Not Beta, it's a maintenance release that's replacing both v1.9.7 and v1.9.9 which have now been removed. Steve N5AC just announced it. Less than 30 minutes after I downloaded a fresh copy of 1.9.7 and tried that as a GPSDO fix. I might now have the final copy of v1.9.7 . I'm still stuck in holdover, but I really wasn't expecting any improvements from this new release. Still waiting for the automagic to kick in.

 SDRgadgets

73, Jay - NO5J

Jay Nation

Salvador
It's a mystery, It was working fine or me on all the releases too, as recently as last Friday, with v1.9.9.
After reading this thread, I powered up the radio this morning, and it was stuck in holdover. So I made sure the GPS antenna had a good connection, rebooted the radio and the PC, then removed power from the radio for about 5 minutes, and booted it back up, and it goes straight into holdover after the warming up phase completes. a couple of times I've seen it find a few of the satellites and indicate it was tracking 4 of them, it then act's like it might be resetting, indicating 0 visible satellites and Then goes into holdover. Normally it finds 12+ visible satellites and indicates 7 - 9 tracked. I'm nearly out of ideas. So, for now, I'm waiting for it to resolve itself like it has in the past.

 SDRgadgets

73, Jay - NO5J

EA4GLI

You are describing exactly the behavior I suffered when water messed my antenna.

Jay Nation

And now at 00:09Z it's locked. automagic finally kicked in! 
While posting this it switched from Locked, to Locking, and then back to Locked.
 I suspect that may continue. I'll keep watching it.
  
 SDRgadgets

73, Jay - NO5J

Jay Nation

Salvador 
I also had my antenna outdoors, but in a rain protected location "under the overhanging eave of the roof" until I saw someone mention it was supposed to be indoor only. Since then it's been inside on the window glass in the air conditioned hamshack for about 9 months. So it should have dried back out. If it remains flakey, I'll probably buy a new antenna. At the moment it's seeing 13 visible and tracking 9 satellites. which was typically how it used to behave.  I don't think it ever got all that damp outdoors but can't swear that it stayed dry either. It was suspended upside down, and I suppose condensation could have followed the coax through to the interior of the antenna. I'll feel better once it's replaced.
  
 SDRgadgets

73, Jay - NO5J

K3DCW

I'm glad to hear it.  

I'll get my new antenna tomorrow. Although mine have not been outdoors at all (one was never even connected until I was testing), it is possible that they have failed for some reason.  Hopefully the new antenna will solve my issues. 

K3DCW

I've put a new antenna on the system and I still have the same symptoms, although I'm now tracking 11 or 12 of 14 visible sats.  I have a trouble ticket open with Flex. 

Jay Nation

Is anyone certain about the displayed Visible Sat information? I researched it a little yesterday, and I'm unclear if the number represents visible sat's the GPSDO is currently receiving, or it reflects the number of sat's that the GPSDO currently has almanac data for. I see that when the GPSDO determines that the almanac data doesn't agree with reality, that it scraps all the almanac data and starts reacquiring it again, Which might be the cause of 11 visible / 4 tracked resetting to 0 visible. It's supposed to take @ 12 minutes to reacquire a fresh copy of the almanac data. The almanac data is what the GPS uses to figure out where all of the sat's ought to be. The GPSDO needs to track at least 4 identified satellites before it begins trying to lock. The more the GPSDO is tracking the more accurately it will discipline the oscillator. My GPS antenna has an open view of the western sky but likely see's little directly overhead, and likely nothing in an easterly direction. So my question is really how many of say, 14 visible, are actually visible.

Anyway, today the GPSDO is locked 137 visible racked,and other than exercising the SMA connection a couple of times and updating to SmartSDR v1.9.13, I've done nothing. So it might have been coincidental, that I was in holdover as this discussion started.
 
 SDRgadgets

73, Jay - NO5J

K3DCW

For anyone that may come across this post in the future. In the end, I returned the 6500 to Flex Radio for warrant repair. The confirmed that the GPSDO had failed; reportedly one of only a very small handful that have done so.  They replaced the GPSDO and shipped it back out to me. Total turn-around time was less than 48 hours in their hands. 

I'm very pleased to report that everything is now working again as it should.

Dave