DAN DUGAN
> >But the RF levels I'm getting with Mitsui Golds is only adequate, 10%
> >less than I got in the golden age of 63- and 74-minute CDRs.
PAUL ISAACS
>You only need be concerned about RF levels when they are very low.
>From my experience, if you have one disc with 70% relectivity and another
>with 60% reflectivity, it does not follow that the quality of recording is
>better on the higher reflectivity disc. I have found that reflectivity above
>60% is more than adequate and ensures good compatibility .
I wonder how reflectivity correlates with my crude relative RF level
measurement. I think the raw RF level is more related to contrast
(difference between pit and land) than reflectivity. And in my
experience this measure is well-correlated with playability.
>What is more
>crucial is the ratio of the rf level coming from the shortest pit (3T) to
>the rf level coming from the longest pit (11T).
I think by metering the pickup preamp output, I'm looking at a slow
average of pit to land, not short to long pit ratio.
>This should ideally be much
>less than '1' otherwise the CD decoder can get confused and misinterpret the
>length of pits.
>
>This is just one aspect of the quality of a disc. Reflectivity might be
>great, but problems can still occur - e.g. jitter
>
>>Please Paul, can HHB provide a hotter 1x-4x CDR?
>
>As already explained, hotter does not necessarily mean better. It is more
>crucial that you get a good overall balance of parameter specifications.
I agree that there are lots of things I'm not measuring, but when I
can only get around 80% modulation off Mitsui Gold discs where I used
to get over 90% with older stocks, and below 75% fails on older
players, I want more margin of reliability.
-Dan Dugan
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