[TenTec] Enhanced SSB

[al_lorona at agilent.com]

George, 

I'll take this one. While it is true that the channels are 10 kHz apart, in any one geographical area you never have two stations with adjacent channel allocations because the AM signal is wider than the 4.5 kHz you mentioned and the FCC needs to protect stations. So, for example, here in Los Angeles, I don't believe there are any two stations closer than 30 kHz. Most, including all of the high power stations, are at least 40 kHz away from each other.

I did my senior project on a related topic and in doing the research called all of the radio stations here in Los Angeles, and they all told me that they went out to between 12 and 15 kHz audio bandwidth. (This was before the regulatory change mentioned by Paul.) Even my advisor was skeptical; he was the one who forced me to call and speak to the chief engineers themselves before he believed me. 

Regards,

Al W6LX


> -----Original Message-----
> From: George, W5YR [mailto:w5yr at att.net] 
> Sent: Friday, 18 April 2003 2:54 PM
> To: tentec at contesting.com; geraldj at isunet.net; w8au at sssnet.com
> Subject: Re: [TenTec] Enhanced SSB
> 
> 
> Paul, are not AM broadcast stations still assigned 
> frequencies on a 10 KHz
> spacing?
> 
> If so, that would appear to limit the upper end of audio 
> response to about
> 4500Hz, leaving a small amount of guard band between adjacent 
> stations.
> 
> Straighten me out on this one, please!   <:}
> 
> 73/72, George
> Amateur Radio W5YR -  the Yellow Rose of Texas
> Fairview, TX 30 mi NE of Dallas in Collin county EM13QE
> "In the 57th year and it just keeps getting better!"
> <mailto:w5yr at att.net>
> 
> 
> 
> 
> 
> ----- Original Message -----
> From: "Paul Christensen, Esq." <w9ac at arrl.net>
> To: <geraldj at isunet.net>; <tentec at contesting.com>; <w8au at sssnet.com>
> Sent: Friday, April 18, 2003 2:16 PM
> Subject: Re: [TenTec] Enhanced SSB
> 
> 
> > > damping to let the microphone hear only the "golden 
> tones" of the ham
> > > transmitting. AM broadcast doesn't even allow going to 15 KHz.
> >
> > Prior to the implementation of NRSC mask in the early '90s, 
> AM Broadcast
> stations had no upper limit.  The NRSC mask now effectively
> > limits the audio passband to approximately 9.5 kHz....and 
> the service
> still sounds poor despite attempts by broadcast stations and
> > receiver manufacturers to improve the quality.
> >
> > WOR in New York has been experimenting (yes, even 
> broadcasters are allowed
> to experiment just like hams once were) with digital IBOC
> > but the jury is still out on whether it can be a viable 
> mode given sky
> wave propagation, fading, noise & interference, etc.  The
> > IBOC receiver goes into an analog "blend" mode when the BER 
> reaches a
> pre-determined threshold.  I haven't heard it, but I can only
> > imagine...
> >
> > -Paul, W9AC
> >
> > _______________________________________________
> > TenTec mailing list
> > TenTec at contesting.com
> > http://lists.contesting.com/mailman/listinfo/tentec
> 
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>