View Single Post
  #748 (permalink)  
Old February 9th 12, 09:22 PM posted to sci.electronics.repair,uk.rec.audio,uk.tech.broadcast
Ian Jackson[_2_]
external usenet poster
 
Posts: 136
Default Audio Precision System One Dual Domani Measuirement Systems

In message , Michael A.
Terrell writes




Do you know that the channel combiners in a CATV head end
were wired in odd and even banks, on separate groups to prevent IMD
caused in the passive mixing?

It might have depended on whose combiners you were using.

I hadn't heard about this so, one day (it must have been back in the
80s), I decided to do a quick test to see if it was true. To be honest,
I don't think I saw much difference whichever way I grouped the
channels. From what I remember, with the modulators putting each out
60dBmV, all the intermod products were at least 85dB down, and were
rather difficult to measure quickly. Such low levels of intermod would
have had a negligible impact on the overall system performance.



--
Ian