George
the top limit for AM broadcsat rigs is 7500Hz
with 2500 hz guard band. Including harmonic energy, the FCClimit is 30 khz
Bear in mind the spacing of AM stations is done for this reason among others
ron
K3MIY
-----Original Message-----
From: tentec-bounces@contesting.com
[mailto:tentec-bounces@contesting.com]On Behalf Of George, W5YR
Sent: Friday, April 18, 2003 5:54 PM
To: tentec@contesting.com; geraldj@isunet.net; w8au@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@att.net>
----- Original Message -----
From: "Paul Christensen, Esq." <w9ac@arrl.net>
To: <geraldj@isunet.net>; <tentec@contesting.com>; <w8au@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
>
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