[App_rpt-users] Distorted audio in app_rpt/Allstar

[Kevin Custer]

On 9/11/2013 1:56 PM, Bryan D. Boyle wrote:
>
>
> and we humans don't process breaks in audio as we do with visual 
> perceptions.


There is GREAT truth to this statement.

Motorola, back before the era the MICOR radio set was being developed, 
invested great time and money in this very issue.

It is my understanding, from talking to the inventor and several 
engineers that worked at Motorola during the MICOR era that the 
circuitry, which ultimately resulted in the famous M6709/M7716 squelch 
chip, was originally designed for receivers used in NASA space missions 
(moon).  Obviously, it is crucial the circuit opened squelch under the 
slightest amount of quieting.   In addition, it was discovered that the 
human brain had a difficult time understanding words that are broken by 
silence; it is much easier if the unintelligent space is filled with 
noise.  For this reason, what became known as the MICOR squelch was a 
circuit that accomplished this task, as well as having the ability to 
close quickly if the recovered audio was considerably noiseless.

Seasoned operators can put together enough recovered audio to make sense 
out of a broken transmission, and people didn't have to listen to a 
squelch burst if the recovered transmission was fairly quiet.

This circuitry and theory can be reviewed in detail by going to the 
USPTO and do a patent number search;
3628058


Kevin - WJ8G


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