De-Emphasis & Pre-Emphasis?

Saber User · Post by **Saber User** » Tue Jan 22, 2002 2:23 am

Greetings. Can anyone please help me to explain De-Emphasis & Pre-Emphasis in a more plain lay-man term? Thanks in advance.

Saber User

Nand · Post by **Nand** » Tue Jan 22, 2002 2:54 pm

Nand · Post by **Nand** » Tue Jan 22, 2002 3:10 pm

N4UMJ · Post by **N4UMJ** » Tue Jan 22, 2002 5:53 pm

All the Sabers I have come across have had the Preemphasis/Deemphasis selection enabled ("YES" on the RSS) on their channels. And the Pre/Demphasis Default condition that Motorola uses on the RSS is "YES".

As Motorola describes it ..."FLAT AUDIO" is obtained by selecting "NO" in the RSS.

My question is:
Is there a situation where you would want flat audio enabled ?

I tried the Flat Audio setting on a local Ham repeater and the highs and hisses on the receive came out of the woodwork. Selecting Pre/De. back to on ("YES" on RSS) produced a much better mellow sound.

Just had to give it a try....

I know where my setting is staying.

Eddie
N4UMJ

Nand · Post by **Nand** » Tue Jan 22, 2002 7:14 pm

perthcom · Post by **perthcom** » Wed Jan 23, 2002 6:10 am

Pre/DeEmphasis also improves the signal to noise ratio that the listener hears.
Higher frequencies of the voice are boosted at the transmitter (pre-emphasis). At the reciever the higher audio frequencies are rolled off (de-emphasis), this returns the voice back to the original sound, while also reducing the natural background "Hiss" of the reciever as the signal gets weaker. It something akin to the original Dolby systems for cassette decks.

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Nand · Post by **Nand** » Wed Jan 23, 2002 11:49 am

Nand · Post by **Nand** » Wed Jan 23, 2002 7:27 pm