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[sunflute]

Do expensive clock cables make any significant difference?
and if so,

Which ones should I buy?

(I am clocking a fireface800 to a Lucid clock)

Thank you

[John Ivan]

I use high quality  75 ohm CATV cable with good BNC connectors and have no problems. I make them myself.

[Stan Barrington]

Check out bluejeancables.com.They use belden and canare cabling with several options of types and lengths.

[blue_orange]

I use klotz, premade wc cable. Good for the budget and performance ratio. Apogee seems good but rather expenzive  

[Gunnar Hellquist]

Just remember to terminate the cable. Not sure if you boxes has inbuilt termination (often a small button where you can switch it on). Otherwise it is the old T-connector plus termination.

Gunnar.

[bradb]

I think the crimp ends are the only way to go and remain 75Ohm throughout.  If youre soldering, youre changing the coaxial geometry and the characteristic impedance.

markertek has a reasonably priced SPDIF cable.  You could buy the connectors, cable from markertek and a crimp ($16.99) from radio shack and go on a spree.

[danickstr]

to test for 75 ohm accuracy, you have to put the terminator on the end first.  the terminator is what makes the cable's resistance 75 ohms.  it is easy to check by putting a multitester (good one) across the two leads.  infinite or more should be the reading without the terminator, and i'll let you guess what the reading should be with the 75 ohm terminator in place.  if it is not, then try another terminator.  and yes there has to be a t-splitter for the terminator and the second piece of gear to both be connected. i use quad shield rg6 and it is fine.  spend more if you have to.  

if the unit has built-in termination, then it is putting the 75 ohm resistor across the leads for you, and you dont need the bnc terminator

[Gunnar Hellquist]

danickstr wrote on Mon, 30 May 2005 19:32

to test for 75 ohm accuracy, you have to put the terminator on the end first.  the terminator is what makes the cable's resistance 75 ohms.

Well, sorry to be pedantic here. I feel like an old teacher saying it, but it can actually be very important.

As written above, it is only part of the truth. The 75 Ohm really should referr to the characteristic impedance of the cable, not the resistance. They share the same unit, Ohms, but describe different things. Impedance is an indicator of how the cable behaves with alternating current such as radio frequency signals, resistance is how things behave with direct current. Standard multimeters generally measure resistance using direct current.

Characteristic impedance of a coaxial cable in general is dependant on the size and spacings of the inner and outer conductor, and the dielectric in between. The length of the cable makes no difference. Hence it is sort of built into the cable at manufacturing time.

Gunnar.