Barry, James,
Here is what RF speech processing does:
First it converts the AF to SSB (RF), usually a very low frequency, such as
60 kHz.
Then this SSB signal is clipped and filtered.
Finally the clipped and filtered SSB signal is demodulated and converted
back into audio.
By doing it this way, rather than just working with the original AF signal,
harmonics produced by the clipping are at multiples of 60 kHz and easily
removed by a 60 kHz filter. The result is increased speech power WITHOUT
harmonic distortion like you would get when doing it at the AF level. You
can run more compression without getting distortion. This results in a
higher level of average output power from your SSB transmitter.
Viola!
73
Rick
-----Original Message-----
From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com]
On Behalf Of Richards
Sent: Wednesday, November 30, 2011 5:22 AM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Omni Speech Processor
The original TT product information stated an RF type speech processor
is much more effective than an AF-based processor. I cannot say why,
myself, but that is what TT said.
======================================= K8JHR ===================
On 11/29/2011 12:36 PM, Barry N1EU wrote:
> Why wouldn't a properly implemented DSP speech processor be able to
> achieve the same level of compression?
>
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