[time-nuts] Are cable delays frequency dependent?

Hal Murray hmurray at megapathdsl.net
Sat Sep 12 16:33:51 UTC 2009


If so, what's the mechanism?

I know that attenuation is frequency dependent due to skin effect but I can't 
turn that into variable delays.  Is there a magic term I should google for 
and/or does anybody have a good URL?

Context is a memory from 20 years ago.  I think it was a data sheet or app 
note for clock recovery on a T1 line.  Maybe it was just explaining the specs 
for a line amplifier.  The idea was that the recovered clock would shift 
depending on the frequency of the signal.  The frequency depended on the data 
pattern so you could harass the clock recovery by picking nasty data patterns.

I think I almost understood it back then when I had the info in front of me.  
I've tried to remember or reconstruct it a couple of times over the years, 
but I've never been successful.


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