GPS Disciplined Oscillator

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  • Updated 1 month ago
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I'm curious if anyone is using this type external GPSDO with their Flex 6000 series radios?   I've purchased one of these last fall on Ebay and have it running in the shack.  The plan is to feed the new 6600 once it arrives.  I've got the RS232 port hooked to my computer via USB and  running a program called NMEA Time which keeps my computer time updated and accurate. It's works great and runs in the background.  WSJT-x is always synced and decodes. 

 a few screen shots:






Cal/N3CAL
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Cal Spreitzer

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Posted 2 years ago

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Photo of Burch - K4QXX

Burch - K4QXX

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Yes, I use one of these on my Flex-6700.  I don't have the software installed so thanks for posting.  
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Mike - W7TUS

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I use a Thunderbolt GPS with my Flex 6500.  I only use the 10MHZ output of the GPS into the 6500 and it knocks the correction down from around 1500 ppb to around 60ppb.  The software that works well with it is Lady Heather but in my situation I don't use the software just the 10mhz signal into the 6500.  Very happy with it.
Mike W7TUS
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WA2SQQ

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I'm pretty sure that my friend Steve, K3WKM is running this one on his 6500.
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Burch - K4QXX

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Cal, does the RS232 port need a null modem/cable or just a normal serial cable?

Burch
K4QXX
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Phil m0vse

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Yes I use that one and it works very well. I have his distribution amp that feeds all of my radios/transverters.

I also use it as a time source for Meinberg NTP.
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Cal Spreitzer

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Burch,  I'm using a  DB9 male to  USB-A male cable to my computer for NMEA Time.   If you have a RS232 serial port on your computer it should be just a normal one.  When the 6600 arrives I plan on running the 10Mhz output (BNC) to the RCA 10Mhz RCA input on the back of the 6600.

Cal/N3CAL
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WA2SQQ

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Anyone have a link to this item on EBAY?
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Phil m0vse

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There don't seem to be any for sale on Ebay at the moment. I got mine direct from BG7TBL on taobao.com but it you don't understand Chinese, it is certainly an experience (even with Google translate)
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Tom W3FRG

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(Edited)
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Bob Craig, K8RC

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A caution if you are really a hair-splitter:

While the long-term frequency precision of a GPS-disciplined oscillator can be much better than the standard free-running oscillator, the phase noise can be MUCH higher. Since the external 10 mhz signal does not discipline the Flex's internal oscillator, it becomes the primary oscillator and can actually degrade the performance of the transceiver to a measurable extent.

This is especially true in the relatively inexpensive GPS-disciplined oscillators. A unit with low-noise output can cost as much or more than the transceiver.

73, Bob 
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SteveM

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So to be a little more blunt than Tim, Bob's comment is not true.

For anything above a 20Hz bandwidth (i.e., negligible), Flex transceivers retain their own phase noise characteristics when using an external reference. Essentially, the external reference is only used for long term frequency accuracy.
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Burch - K4QXX

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Cal, I am having trouble finding this software.  Can you point me in the right direction? 

Burch
K4QXX
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Cal Spreitzer

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Burch,  NMEA Time can be found here:  

http://www.visualgps.net/#nmeatime2-content

Cal/N3CAL
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Burch - K4QXX

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Thank you.
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Ross - K9COX

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Meinberg works for me
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John - W8AGS

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Has anyone used the Leo Bodnar GPSDO with the 6000 series?

John, W8AGS
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Bob Brown - N8OB

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I use this unit on my 6300.  I use a rubberduck antenna on the 10Mhz connector and then run the calibration procedure on 10Mhz.  It works very well.  I use this system for the FMT and usually do well on it also.  Mine is a couple of versions before yours but it checks out very well.
Bob - N8OB
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John - W8AGS

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Thanks, Bob. I’m going to order one. It has pretty good reviews.

John
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AC9S

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I note the DC requirement on the BG7TBL is 11.7 - 12.9V.  I assume most of these are run from shack supplies which are closer to 13.8.  Any issues?

Keith - AC9S
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Cal Spreitzer

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I've run mine for over 1 year at 13.8vdc.  It's still working.  Only thing I had to do is attenuate the output.  It's original output was a tad over 3.3 volts peak to peak which the Flex 6600 didn't tolerate but I padded it down to 2.0 volts and no issues.

Cal/N3CAL
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AC9S

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Thanks for sharing.

Keith