[Elecraft] Attenuator and RF Gain Settings

[Jim Brown]

On Tue, 02 Feb 2010 16:34:50 -0500, Don Wilhelm wrote:

>BUT one *can* make that happen with incorrect settings.

YES! Don has given us a LOT of great advice in his two recent 
posts in this thread. Let me emphasize something that I'm sure he 
understands, but didn't make quite it clear if you didn't read 
between his lines. 

NOISE IS PART OF THE SIGNAL THAT IS DRIVING THE AGC. IT IS ALSO 
PART OF THE SIGNAL THAT IS GENERATING INTERMOD, BOTH AT RF AND AT 
AUDIO. IT IS PART OF WHAT THE IF SELECTIVITY MUST REJECT, JUST 
LIKE ANOTHER STATION!  

CAPS ADDED FOR EMPHASIS. 

If the NOISE overloads the signal chain, the resulting distortion 
obscures the signal. It is not enough to keep the signal chain 
below overload on signal. We must also keep it out of overload by 
noise pulses. That's not easy, because much of the noise at the 
antenna terminal is impulsive in nature -- certainly static and 
stuff like fences. 

Bear this in mind when setting ATT, PRE, RF gain, and AGC 
parameters. 

73,

Jim K9YC