[time-nuts] New topics (was Re: He is a Time-Nut Troublemaker....)

Hal Murray hmurray at megapathdsl.net
Tue Dec 23 18:58:58 UTC 2008


> 2.  Several measurement techniques require a given phase relationship
> (e.g., quadrature) between DUT and reference.  For HF frequencies (ie,
> 5  or 10 MHz) is there a *practical* phase shifter design covering
> 180+  degrees that doesn't involve switching various lengths of coax
> in and  out of the line? 

PLL up by a factor of N, use that to drive a DDS, then filter.  Maybe a pair 
of DDSes will get better tracking.

For each possible phase offset, you need N slots in the table.  (N/4 with 
more work)

-- 
These are my opinions, not necessarily my employer's.  I hate spam.






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