[hpsdr] GPSDO

[Mike Seguin]

Glen,

You are seeing perfectly normal operation for these GPS engines.

Does yours have a supercap? (backup battery) If not, you can add one so 
you don't have to go through a cold start every time you power it up or 
there is a power failure.

Mike

On 3/8/2017 6:56 PM, K4KV wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> Hello,
>
> I wanted to report back that those $12 Navman GPS modules off of Ebay
> work fine.  Using
>
> VisualGPSView, they obtained fixes after several minutes.
>
> My board would not lock onto the signal on either of these boards, but I
> do not believe it
>
> has anything to do with the GPS modules.  I can see rapid changes in the
> 10Mhz signal to the Hermes
>
> as if the loop filter values are not correct.  I had long since taken
> the wires off the board so that I
>
> could monitor the loop filter with the scope.  These modules model # end
> with 041 while my original ends with 021.
>
>
> I spent some time monitoring the 10Mhz accuracy on WWV using the
> Spectrum view program.  Even though
>
> the VisualGPSView said I had a GPS Fix, the clock was still not
> accurate.  It took some minutes more, after the
>
> first 'fix', then all of a sudden I saw the altitude, lat and long, move
> a bit to a number I know is right.  Then
>
> WWV was correct, with the tones within 1 Hz.
>
> 73
>
> Glen K4KV
>
>
>
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-- 

73,
Mike, N1JEZ
"A closed mouth gathers no feet"