[AMPS] amplifier "audio"

Tue, 10 Jun 1997 10:55:54 +0000

> Yes, RF amplifiers can and do modify the audio response of a signal, both 
> "good and bad".  A few of the AM broadcast transmitters I've death 
> with have sections in their manuals regarding amplifier operation for 
> certain "types of fidelity". This also includes interfacing to various 
> antennas which also modify the audio.
> One manual had tune up instructions for music vs talk radio format! Go 
> figure...

The problem with AM BCB comparison is one of bandwidth as a percentage 
of frequency and accumulated Q in the system.

A 20 KHz wide (with 10 KHz upper modulation frequency) or wider 
signal is a large percentage of the operating frequency. 

The amateur SSB signal contains its useful information in under 3 
KHz of  bandwidth at more than twice the operating frequency. That 
makes it over twelve times less sensitive to system Q.

When Hams used AM their signals used to be subjected to selective 
fading and distortion (mainly on 160 and 80), but when is the last 
time you heard phase distortion on a SSB signal?

Amplifier bandwidth and phase shift is unimportant in HF and 
higher SSB voice systems, and it has nothing to do with splatter 
anyway. 

73, Tom W8JI 

--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm