[time-nuts] T.I. experimenting - newbie question

[Joseph Gray]

If I understand you correctly, then I did not have things setup
symetrically. Now I have a tee on each of the A and B inputs. The
unused port on the B tee has a 50 Ohm terminator. Is this what you
mean?

With the above setup, using the shortest cable I have gives me 1.5 ns.
Adding the longer cable to the shorter, using a F-F BNC coupler gives
me 21 ns, for a difference of 19.5 ns. The readings are bouncing
around a bit, so these numbers aren't exact. Using the 19.5 ns figure
and a 66% VOP, I get 3.86 M, which is much closer to the measured
length.

If I use the calculated length vs the measured length, I get a VOP =
65%. Pretty close to the specified 66%.

Thanks to everyone for the help. Any more hints or discussion are
always appreciated.

Joe Gray
W5JG

On Sat, Apr 2, 2011 at 8:55 PM, Hal Murray <hmurray at megapathdsl.net> wrote:
>
> You want the difference in path lengths.  Is there an asymmetry in the setup?
>  If so, count the BNC connectors that don't have a match on the other path.
>
> If you have input-Tee-coax-Tee-terminator, then the difference is the coax
> plus half of each Tee.  That is you want to measure the length from center of
> Tee to center of Tee.