OSU Channel Link Cable test results:

The test was done in mid-Feburuary 1999.
A 16-bit binary counter running on the Channel Link clock was the default pattern generator for the Channel Link.

Cable types tested:

Flat Shielded Ribbon
Unshielded Twisted-pair
Round Shielded Twisted-pair
Flat Shielded Twisted-pair
Twin-axial (individually shielded twisted-pair)

Test Results:

1. Flat Shielded Ribbon Cable: (Overall Shield)

Cable Length	1m	3m	6m	8m
Error Rate (20MHz)	0	0/10Million (0%)		1328/6209536 (0.021%)
Error Rate (40MHz)	0/8Million (0%)	0/2Million (0%)	492862/3397705 (14.5%)	67227/98304 (68.4%)
Error Rate (40MHz, Swap pins*)			19061/6340608 (0.30%)

*Swap pins: put a groud pair between each signal pair to isolate crosstalk.

2. Unshielded Twisted-pair Cable (Clock Frequency 40MHz):

Cable Length	6m	8m
Error Rate	0/14Million (0%)	0/20Million (0%)
Error Rate (Folded Cable*)	0/2Million (0%)	55193/3432448 (1.61%)
Error Rate (Folded* with twist--Pin 1 to pin 50)		8832/2621440 (0.34%)
Error Rate (Folded* but isolated with separate Cable)		9528/204800 (4.65%)
Error Rate (Swap Pins, Folded*)		0/14Million (0%)
Error Rate (Cable layed out for maximum RF pickup)		0/4Million (0%)

* Folded cable: test self-interference of cable by folding it up.

3. 6m Round Shielded Twisted-pair Cable (Overall Shield, Clock Frequency 40MHz):

Error Rate	Error Rate (Grounded Shield Drain)	Error Rate (Swap Pins)
6756/2090768	22878/6275072 (0.36%)	40774/14909440 (0.27%)

4. 8m Twin-axial cable (Individually Shielded pairs, Clock frequency 40 MHz)

0 error for 110Million Words

5. Flat Shielded Twisted-pair Cable (Overall Shield, Clock Frequency 40 MHz, Ground pair between each signal pair)

Cable Length	8m	10m
Error Rate	0/>3Billion (0%)	56232/4112384 (1.36%)
Error Rate(Change counter to 8-bit up-down)	0/90Million (0%)

Cable Test setup:

Summary:

Twin-axial Cable works at 40MHz at 8meters.
Flat Shielded Twisted-pair Cable (with a Ground pair between each signal pair) works at 40MHz without error at 8meters, but fails at 10 meters.
Found: D0, D7 and D14 are more than 10ns later than other data bits for the TTL outputs of channel link receiver at 20MHz, and about 4ns at 40MHz.