[BC] Digital Interference (was AM Interference)

[Rich Wood]

------ At 11:56 PM 12/17/2005, Robert Meuser wrote: -------

>NPR is also a disappointment, no multicasting on FM and the AM 
>station sounds awful a lot of the time, too many cascaded CODECs and 
>that is when the radio can decode the digital.

Unfortunately, Western MA just lost its one HD listener. I returned 
the radio I was loaned. We're fortunate that WFCR at the University 
of Massachusetts has a great sounding NPR station. They're using the 
secondary for NPR's talk programming and keeping Classical Music on 
the analog and main digital channels. They've had a lot of trouble 
with their exciter, so for much of the time I had the radio their 
digital was down.

I know their Chief hadn't had time to tweak the processing, so I 
heard artifacts on stringed instruments and voice. They're not 
processing separately. Since they don't process heavily I've always 
been able to hear the "punch" of Classical and Jazz mixes, so I 
expect IBUZ, for them will do little more than get rid of multipath 
that barely exists here. The only upside is the addition of the Talk 
secondary which is like the tree falling in the forest with no one to 
hear. To hear WFCR's secondary I have to listen to WAMC's, Albany, analog.

Why is WNYC-AM so difficult to receive in IBUZ? Didn't they increase 
power to 20Kw when they moved in with WMCA? Wouldn't the digital 
power be nearly comparable to WOR? Of course, I lived on the Hudson 
River at Horatio St. and received WNYC-AM and WMCA directly over 
Water. Very strong signals. According to Tom and Kerry at WOR, 
digital makes formerly unreceivable signals crystal clear. It should 
be very easy with a stationary receiver. IBUZ is the closest to 
salvation we'll see on Earth.

I don't understand why people haven't looked closely at Herb Squire's 
experiments and warnings about cascaded codecs. It seems a no-brainer 
that each codec removes a piece. What's left at the end of the line? 
It would seem logical to me that cascading the same codec wouldn't be 
a problem. After the first one, there's nothing for the remaining 
ones to remove. Using different ones takes different pieces at each step.

Would any of this meet the red book requirements for CD Quality? I 
wish the term CD Quality had the same protections as things like THX. 
Either it meets the standards or they'll sue you for using the term. 
Today, anything that makes noise is CD Quality.

Rich


Rich Wood
Rich Wood Multimedia
Phone: 413-303-9084
FAX: 413-480-0010