I am not going to wade back into part 97 for this, but I believe 5 khz audio
is beyond the scope of being communications quality. I know a number people
who have a lot of rebuilt broadcast audio gear and are also audiophiles,
many in the pro audio business and they are really in to this. Regardless,
more than 3 khz if not blatantly illegal is certainly not what the FCC
intended.
From: "John B. Stephensen" <kd6...@comcast.net>
Reply-To: <digitalradio@yahoogroups.com>
Date: Mon, 22 Feb 2010 20:27:41 -0000
To: <digitalradio@yahoogroups.com>
Subject: Re: [digitalradio] FCC Technology Jail: ROS Dead on HF for USA Hams
The 300 baud limit applies only to the HF RTTY/data segments. In the
phone/image segments below 29 MHz there s no baud rate limit but the
bandwidth is limited by the following parts of 97.307(f).
(1) No angle-modulated emission may have a modulation index greater
than 1 at the highest modulation frequency.
(2) No non-phone emission shall exceed the bandwidth of a
communications quality phone emission of the same modulation type. The
total bandwidth of an independent sideband emission (having B as the
first symbol), or a multiplexed image and phone emission, shall not
exceed that of a communications quality A3E emission.
Given the width of some amateur AM signals on 80 meters, this limit seems to
be 10 kHz below 29 MHz.
73,
John
KD6OZH
>
> ----- Original Message -----
>
> From: Trevor . <mailto:m5...@yahoo.co.uk>
>
> To: digitalradio@yahoogroups.com
>
> Sent: Monday, February 22, 2010 09:18 UTC
>
> Subject: Re: [digitalradio] FCC Technology Jail: ROS Dead on HF for USA Hams
>
>
>
>
>
>
>
>
> However, there may be scope in interpretation of the regs. Up until a few
> years ago many US amateurs were under the impression that you could only send
> a maximum of 300 bits per second on HF. What the rules actually specified was
> a maximum symbol rate of 300 Baud and, probably because no had thought to do
> so, there was no limit specified on the number of carriers you could
> transmit. That's how these days US hams can run digital voice/sstv.
>
