[Elecraft] RF gain sweet spot

[Merv Schweigert]

Was interested in this thread and find that my K3 does the same thing,  
but takes a
"vernier" touch to see it,  very slight movement of the pot at about 
the  2:30 to 3 oclock
position causes the S meter to "dip" down about 1 bar.   Never noticed 
it because
of the very small area, one passes by so fast you will never see it.
I also find thats about where I run my RF gain almost 99 percent of the 
time,
Its not the dip that means anything at all,  its where you run the RF 
gain that is
what works.   With this many K3 exhibiting the same thing its not the 
gain pot,
its something in firmware,  which as far as I can tell does nothing at 
all other
than its the same place approx where its a good spot to run the RF gain.

Merv K9FD/KH6
> It is possible that there is a problem in the RF gain pot.  It IS a
> potentiometer.  It has a standard voltage across it, and the variable
> voltage in the pot's "wipe" is sent to an analog to digital converter,
> which converts the pot setting to "numerical advice" which can be more
> easily sent to the CPU over one of the various digitally multiplexed
> communication busses.
>
> It could be a non-linearity in the potentiometer, where on a normal
> K3, the "sweet" spot would be a point in the gain setting where the
> absolute unchanging difference between signal and noise is interpreted
> most favorably by the ear/brain which has its own way of hearing. That
> trick has been around for a long time.
>
> 73, Guy.
>
> On Fri, Jul 22, 2011 at 11:17 AM, K7WIA<emoss98133 at msn.com>  wrote:
>    
>> Geoff...  my K3 only has the one filter in it at the present time, so I can't
>> check that out for you.
>>
>> Ed  K7WIA
>>
>> --
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