[time-nuts] Correcting jitter on the 1 PPSsignalfromaGPSreceiver.

SAIDJACK at aol.com SAIDJACK at aol.com
Mon Sep 15 15:06:32 EDT 2014


I don't claim to be able to do the math, but one could probably easily  
calculate it from the Fourier frequencies by looking at the attenuation by  
frequency over a 1km lengh:
 
Loss per 100m over frequency:
 
10M    100M    400M    1300M    2300M
7dB    14dB    28dB       49dB    72dB
 
So looking at these numbers I am guesstimating a risetime in the us  
alongside a good handful of microseconds of propagation delay.
 
bye,
Said
 
 
In a message dated 9/15/2014 11:31:28 Pacific Daylight Time,  
hmurray at megapathdsl.net writes:


>  Also, another issue with the end termination happens when driving very 
long  
>  coax cables: RG-142 for example has about 60 Ohms center  conductor
> resistance  and 7.5 Ohms shield resistance at 1km  length. 

RG-142 is far from low-loss.  Does anybody use it at that  length?

What's the rise time at the end of 1 km with a 1 ns rise time  at the input?



-- 
These are my opinions.  I hate  spam.






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