[Elecraft] RX Mush, why the fuss?
Don Wilhelm
donwilh at embarqmail.com
Tue Feb 28 20:34:41 EST 2017
I am not certain what it has to do with "mush", but it does seem to help.
What is certain is that if the AGC Threshold is set too low, the AGC
will be activated on band noise. Whether that 'band noise' is the
result of ambient noise level, or the ambient 'noise' of a multitude of
signals in close frequency proximity is for the user to determine.
As far as the slope is concerned, yes, the AGC will respond to the
strongest signal in the passband, that is a fact.
The reason for setting the slope to something other than flat is not a
consideration for reducing the RX Mush, but it allows the user to
evaluate by ear the relative strength of signals.
In summary, signals below the threshold will be received the same as
with the AGC off. Signals above the threshold will be reduced according
to the slope of the AGC response, but the strongest one in the passband
will take control of the AGC.
It is nice to be able to report an S6 signal is weaker than an S8 or S9
signal without depending on the S-meter. Of course, all signals in a
contest or for reports to a DX station are always 59 or 599.
On 2/28/2017 6:37 PM, dave wrote:
>
> My thoughts on this are that those who are concerned about the slope and
> threshold settings are barking up the wrong tree. The mush would result
> if you have your hold time or hang time or decay set too short. With a
> brief hold time the weaker signal pops up to the level of the stronger
> on as soon as the stronger one disappears. A longer hold time keeps the
> relative level of the two signals at the correct relationship. The
> answer is hold time, not threshold or slope.
More information about the Elecraft
mailing list