[BC] AM Stereo

[Jerry Mathis]

Replies embedded.

--
Jerry Mathis

On Thu, Nov 25, 2010 at 1:26 PM, Barry Mishkind <barry at oldradio.com> wrote:
>At 11:59 AM 11/25/2010, Jerry Mathis wrote:
>>The problem is, the receiver manufacturers NEVER CAME THROUGH with their side of the bargain. They continue TO THIS DAY to make crappy AM radios with an audio frequency cutoff somewhere down around 3 kHz now. I don't even try to listen to AM anymore. Unless you've got REALLY GOOD audio processing, everyone talking on AM sounds like they have their hand over their mouth. My degraded hearing accounts for SOME of that, but not all.

>       I really hate to re-enter this discussion, but since it is
>       wandering and we are now shouting.....

>       1. The manufacturers have done only what they needed
>       to do to prevent millions of cars being returned for
>       having "defective" radios. Argue all you want. Their
>       goal is not to have "the best audio" .. it is to have the
>       least service requests.
 
But weren't the NRSC modifications supposed to solve that problem? By cleaning up the splatter and monkey chatter? Wasn't that the goal?
 

>       2. The broadcast industry shot itself in the foot on this
>       one. The relentless Modulation Wars and pre-emphasis
>       hyping caused so much inter-channel chatter that the
>       only defense was to reduce the bandwidth.
 
I agree, but after NRSC we were all supposed to follow the new standards, again, which was supposed to FIX THE PROBLEM?
 

>       3. If broadcasters had not been so fixated on 99.9%
>       negative modulation, the Magnavox AM Stereo system
>       (the topic of this thread) would have worked just fine.

>       In fact, I would think that the true experts on this list,
>       like Bob Orban or Greg Ogonowski (the others are
>       lurking - we haven't seen much from them in a while)
>       would suggest   that anything over 92% negative probably
>       causes more distortion than loudness.
 
I've read articles on this subject, and I tend to agree. In fact, I'm trying to FOLLOW this advice at the AM Stations I care for.
 

>       4. Without the NRSC "truce" (a little better than the
>       Korean War truce ...) the escalating pre-emphasis
>       would have brought AM bandwidth down to almost
>       nothing.

>       With the NRSC "truce" we have a sort of "status quo."
>       The existing pre-emphasis curve and the car bandwidths
>       are about as good as can be expected.
 
"As good as can be expected" is a FAR CRY from what was promised of the new standards. And this is the big cheat that was foisted on AM broadcasters AFTER we adhered to the NRSC standard.
 

>       5. It isn't possible broadcasters could "back off" a bit now
>       to tempt the manufacturers to "open up" ... the proliferation
>       of signals on the AM band - including the high power,
>       hyperdirectionals with their off-carrier sidebands - has
>       been as detrimental to AM reception as the increasing
>       man-made RFI.
 
The whole point is MOOT at this time, anyway. No one really cares anymore. Frankly, IBOC on AM would (does) destroy any beneficial effect of NRSC compliance by either broadcasters OR receiver makers. And stations with off-carrier sidebands need to comply or shut down. It's looking more and more like AM may get to migrate to a new band, and ultimately leave a few superpower AM stations behind. What happens to them, will be up to them to remedy.
 

>       Really, between the industry wars and the timid FCC, it is
>       broadcasters themselves - the same bunch who
>       decided to automate stations to save money - who
>       have really made the mess.
 
This is not said in anger, but you are blaming the victims for the crime. While the trend to automation began before AM Stereo and NRSC, the trend continued because of the continued listener drain. Decent radios MAY have made a difference for many AM stations. Yes I agree, the industry did itself a lot of harm--but improved audio quality COULD have turned a lot of that around, IMHO.
 

>