GPSDO externe

on5po · May 2020

Good morning all ,
I'm looking for help
I bought, an external GPSDO (without brand), from a flex seller here in Europe,
Difficult to have a correct procedure for use on my flex 6700 version 2.6.1
I connected the cables well, switched on, after 17 minutes, the lamp, red, which should go out when the number of visible satellites is sufficient, it goes out.
my questions, in the "setup, GPS" should I have the number of satellite altitudes etc ...
here empty
to perform the control, in what mode should I put the flex and on what frequency. can I perform the "start" maneuver in the "RX" section of the setup, to see the result.
Thank you for helping me, with a walkthrough
73 de on5po, Janny

KD0RC · May 2020

Hi Janny, yes, just click the Start to begin the calibration. Make sure that you have an antenna on the Ant1 connector, and that you can hear the calibration station (WWV here in the US), and that you have that frequency entered in the Cal Frequency box.

73,
Len, KD0RC

Steve VanWambeck · May 2020

The GPS information will only be available using the internal Flex GPSDO.

73 de Steve, N9VW

Martin AA6E · May 2020

The only way your external GPSDO can work with your Flex is by supplying a high stability 10 MHz reference to the Flex external reference input. The Flex SSDR will not know about your GPS details, but you will get the high accuracy you want. 73 Martin AA6E

Brian Denley KB1VBF · May 2020

He won’t need any calibration station. The program will just use the external 10 MHz GPSDO signal to calibrate. But he will need to press START.

KD0RC · May 2020

Hi Brian, I believe that it works the same way whether it is the TCXO, internal GPSDO or external GPSDO. It locks in on whichever oscillator source it has, then uses whatever calibration sig is specified (e.g. 10 MHz WWV). In my case, WWV at 2.5 MHZ gives me an adjustment of -3 ppb when using the GPSDO. Using the TCXO, it gives an adjustment of somewhere around -1200 ppb. If you were to manually set the adjustment to zero with a GPSDO, you would likely be within a fraction of a Hz anyway, so I recognize that it is not critical to do the cal in that case. 73, Len, KD0RC

Brian Denley KB1VBF · May 2020

Exactly. I was just pointing out the he didn’t need to hear any cal station. Just press start.

on5po · May 2020

Thank you for the explanations ,
with the external gpsdo, no need, so to put me on WWV, ok, but to do the "start" test, I have to put "start" in which mode, and on what frequency
73 of on5po, Janny

on5po · May 2020

Good morning all ,
after sleeping on it, I recap, what I understood,
the external GPSDO replaces the WWV signal received by my HF antenna
It does not allow to have information, like the number of satellites, longitude / latitude, etc, as allows an internal GPSDO from Flex, it allows by turning off a lamp to say after a certain time, that it has several satellite reception.
If this is the case, if you do not intervene manually for a calibration, the gpsdo, it will not do it for you automatically
There, I think I understood correctly.

my question (again), with an external gpsdo, I have to put the flex, on the frequency 10 Mhz and do the calibration as did without gpsdo, but under what mode AM, CW or .....? it seems to me having seen, that the flex automatically puts on AM as soon as the test is requested,
thank you for specifying me, the first maneuver to do, on 10Mhz in what?

Sorry to bore you with my ignorance, I am sure that it will be useful for others, especially not to make an inconsiderate purchase,
73 on5po, Janny

Larry _ NY8T · May 2020

When you have an external GPSDO connected to a 6700, 6500, 6300 you will not see any indication that it it working on the settings/GPS tab. When you push the START button on the RX tab, it will automatically change the radio mode to AM and to the WWV frequency you have specified then do the calibration and when its done it will switch your mode and frequency back to where it was before hitting the START button. The only thing you need to make sure is your antenna is on ANT1 and it is receiving the WWV signal good enough to do the calibration.

Image httpsd2r1vs3d9006apcloudfrontnets3_images1834658RackMultipart20200503-118719-gxusfw-calibrate_inlineJPG1588509007

on5po · May 2020

Thanks Larry,
why, I still have this difference of -2677 ppb, even if I repeat the calibration
is this normal?
I am with the external gpsdo, I put myself on 10 Mhz with the flex

Image httpsd2r1vs3d9006apcloudfrontnets3_images1834659RackMultipart20200503-53937-1srd1pf-gpsdo_pour_flex_inlinePNG1588512048

on5po · May 2020

I notice in relation to your image, I don't have "Binaural audio" Enabled, should I check it?

Logan KE7AZ · May 2020

The 6300, 6500, and 6700 only check for an external reference on power up. I’d suggest you turn your radio off, make sure the external GPSDO is on and locked, then turn your 6700 on. It should lock to the GPSDO during power up. Logan, KE7AZ

on5po · May 2020

Logan,
A big thank you, a very good suggestion, now 23ppb
I think we've covered the subject,
A big thank you to all
73

KD0RC · May 2020

Start only works with an off the air cal station. Without a cal stn, you can just enter ppb to manually adjust (typically 0 if you use a gpsdo). Here is an experiment that shows how it works. With the gpsdo running, type 1000 into the ppb adjustment box and hit enter. Now go to WWV and see that you are off freq. Press start, and see that WWV comes up in AM mode, and the ppb moves to some small number. If no cal stn was involved, you would just enter an adj of zero in ppb. Make sense? Len

Brian Denley KB1VBF · May 2020

I connected my gpsdo, pressed start and it came back with 0 one time, 3 another. I checked against WWV and it was perfect. I just assumed that was the way to do it since it worked so well.

KD0RC · May 2020

Yep, it worked because there is a WWV freq listed in the Cal Frequency box. If it finds a sig there, it calibrates that last few PPB out. If not, I think it just goes with whatever it finds (noise?) and gives a bogus adjustment. Given that we are talking about a fraction of a Hz, setting the adjustment to zero and don't hit the Start (if you have a GPSDO) will work fine if you don't have a good cal sig to work with. I am only an hour's drive south of Ft. Collins, so I get WWV really well...

73,
Len

GPSDO externe

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