Charlie wrote:
Roy the kind of test results you cited would be extremely evident whether
someone has a network analyzer or just an swr meter.
That defense is sorely transparent in my opinion. To suggest that most
amateurs would not even have any interest if their bent or coiled 9914
suddenly jumped off the scale for loss and mismatch is ludicrous to say the
least.

Would you really notice if your cable loss was about 3 dB higher than
specified at 400 MHz and if it varied by a dB or two when the cable is
flexed and bent? What measurement equipment do you use which would cause
this amount of extra loss to "jump off the scale"? And what causes you
to think that increased loss would cause mismatch to "jump off the
scale"? Increased loss will improve, not degrade, the impedance match.

Let me be clear ...I am not disputing what you claim you got as test
results. My conclusion is either the 100ft length you had was bad or
something skewed your calibrated setup.

What you have as evidence is Davis' spec on the one hand, and my
measurement report on the other. You've chosen to believe that Davis'
cable all meets its published specifications. I have exactly the same
evidence, but know my capabilities and that of my equipment, so I
believe my measurements -- but always keeping in mind that it's a single
sample. Additional measurements made by someone else on another piece of
the cable would increase the knowledge base, although I'm sure there are
people who would choose to ignore the evidence no matter how much is
presented.

My career was in microwave r&d and
I know that it takes repeatable test results to form a valid, verifiable and
publishable data.

That's great! Then you have the background to be able to make decent
measurements, and you said you're using some of the cable. Why not just
measure the loss in a length of it and report your results?

This is not personal Roy....but it is somewhat stimulating.

I hope it's caused a few people to think a bit about how they evaluate
evidence to determine the truth of a matter. It's something which too
many people are woefully unable or unwilling to do.

Roy Lewallen, W7EL