[BC] I don't want to go away

[Rich Wood]

------ At 11:47 AM 1/22/2006, Barry McLarnon wrote: -------

>Ah, that's the rub: this is not a debugging exercise.  We're faced not with
>bugs, but a fundamental design flaw.  There is no engineering solution,
>short of throwing the system on the scrap heap and starting over.

Actually, I disagree (assuming IBUZ follows directional rules). Once 
digital receivers are out there in Arbitron reportable numbers 
daytime only operation of digital won't fly. We'll have to figure out 
how to protect stations by changing our arrays in ways that keep the 
analog where it's supposed to be and controls the adjacent channel. I 
don't see this any differently than protecting stations head on on 
the same frequency. FM stations are splitting their analog and 
digital feeds. Can it be done with AM? Maybe a separate array for 
digital. Maybe a hybrid type of array that uses the current towers 
with a couple added to reign in the digital. If we're willing to add 
10 towers for a rimshot 50Kw. nighttime signal, one or two should be 
manageable.

If stations keep in their own yard they can do anything with their 
signal they want. Doesn't matter to me.

My real problem with FM IBUZ is the dumb way it's being rolled out. 
Promoted much too early when the devices we really need to compete 
aren't even off the drawing board. CBS Marketwatch did a piece this 
morning on new electronic gadgets. The Video iPod led the way. 
Virtually everything was handheld. Every single manufacturer 
interviewed agreed that content will drive everything. I don't 
believe Wurlitzer without the choice will work. We need real radio 
stations on secondaries. That's expensive when there aren't even 
enough receivers in total to qualify for Arbitron reporting even if 
they were all in the same market.

>The hybrid FM IBOC system is a nasty design that spews all of its digital
>noise on the adjacent channels.

With the Kenwood receiver I found no FM interference problems, at 
all. I drove approximately a 100 mile radius. Albany to Boston from 
my home midway between. I found some very bad implementations of IBUZ 
but no adjacent channel interference. As I said, trash your own yard 
and I don't care. Just stay out of mine.

>  A case can be made, however, that there
>is a worthwhile tradeoff here.  Analog coverage will be negatively
>impacted in some cases, but one gains the capability of delivering
>multiple audio services that are relatively immune to multipath problems.

I'm glad you added "relatively." IBUZ added its own annoyances in 
areas with intermittent low signal areas. Not a deal killer but not 
the perfection the press releases claim. I found it better to force 
digital to avoid mode changes that were more annoying than an 
occasional loss of signal. I'm used to loss of signal with satellite 
in New England where trees overhang the highway. Even GPS can be a 
problem. With the auto mode setting it kept switching from digital to 
analog and combined the worst of both worlds.

>There will definitely be some losers on the FM band (rimshots, LPFM's,
>etc.), but it can at least be argued that it is an overall win for the
>industry.

Rimshots and LPFM have never been among broadcasters' beloved. 
Rimshots have been seen as interlopers, abandoning their cities of 
license. We won't get much sympathy for them. It's almost poetic justice.

>No such argument applies to the AM IBOC system.  The AM band is totally
>unsuitable for the hybrid approach that uses the adjacent channels for the
>digital add-on.  It's simply a train wreck.

That's really a shame. The quality difference on FM between analog 
and digital is subtle (in my experience with the receiver). Only one 
station was processing separately, the rest were smashing and mashing 
the audio as usual. In strong signal areas there was no difference in 
level or quality between modes.

The most dramatic audio improvement was on AM. WBZ, Boston, seemed to 
be processing lightly in digital. Compared to their analog it was 
much easier to listen to. Up the street on Mt. Tom WBZ's digital 
signal was clean about 125 miles away. Sidebands were noisy but the 
audio quality was a great improvement. KDKA at 1020 was nowhere to be 
found until exactly 6pm.Then it bombed in. WTAG in Worcester, MA, was 
a slight improvement but the artifacts were annoying. Most likely a 
processing issue.

I want to see digital for AM. Instead of dumbing it down to 5KHz I 
want to hear the quality the press releases claim.

Rich


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