[ntp:questions] GPS_NEMA, but high offset and jitter?

Joseph Gwinn joegwinn at comcast.net
Mon Mar 1 14:23:40 UTC 2010


In article <7v1k7fFipuU1 at mid.individual.net>, David Lord <snews at lordynet.org> 
wrote:

> unruh wrote:
> > On 2010-03-01, Kelsey Cummings <kgc at microshaft.org> wrote:
> >> David J Taylor wrote:
> >> ...
> >>> I would knock something up if there were enough interest, but it would
> >>> be a Windows program so of limited interest to the OP.
> >> That's the idea anyway.  At the time, I was convinced the PPS signal was
> >> showing clearly and it was but with the led transistor in backwards the
> >> PPS line was getting pulled down to 1.4v or thereabouts.  Not enough for
> > 
> > Hard to know how it would do that. 
> 
> Transistor inserted with reversed C/E have low Vce breakdown,
> very low gain and possibly higher Vce_sat. They still operate
> as transistors and long time ago I've used in that mode but I
> can't remember what that was for (not so long after red spot
> or white spot transistors were sold in a box of one which cost
> a quid = eight weeks pocket money).

Inverted bipolar transistors were widely used as choppers (in synchronous 
detectors), as the offset is lower in that configuration.

Joe Gwinn




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