[Elecraft] Re: K3 AGC Adjustment Parameters

[Don Rasmussen]

Hi Wayne,

As -always- thanks so much for listening. 

This is not a trivial issue for me, it's the "glue"
that brings all the other aspects of the transceiver
into line. 

Here's the list in priority order, what I'm looking
for in a flexible AGC:

1. Slope - I want S9 CW signals to sound stronger than
S2 signals (more AF) when using a speaker, filling the
room with signal. When using headphones I'd like to
dial it so the signals are at the same level. This
setting was not changed. 8-)

2. Threshold - this is possibly somewhat redundant
with SLOPE, but I'd like the AGC for CW to behave as
if it's in the OFF position until (example) S5, then
to become active. The threshold would change
appreciably by band and noise level.

3. Decay - this is more for phone modes, especially
AM. I'd like an S9 AM carrier when unkeyed to slowly
decay to the squelch at the rate that I choose. CW
would be the fastest decay.

4. Hold - (Hang AGC?) I guess this is Ten Tec
emulation mode. ;-) I don't have much use for this,
but would use it for phone modes occasionally. I'd
rely on DECAY the majority of the time. 

5. Attack - this one, well really isn't that critical
either for my operation, if THRESHOLD is available,
but some others may have modes where this would be
beneficial.

In the past I have been amazed at what sounded "good"
with some of my friends. IC756Pro in Full NR for
example does not even sound human to me but some
others hate band noise so much it makes sense to them.


So as long as there is a defaults reset, I lean
towards customization. Those of us that have fiddled
with hardware AGC circuits realize the large practical
benefits in being able to shape it. 

C U 

Don



Don Rasmussen wrote:

> I don't know about anyone else, but I bought K3
based on being able
 to 
> adjust these (5) things.

Don,

It was my decision to remove them, for the reasons
given below. It's 
trivial to add them back in, but debatable as to
whether it's a good 
idea. I'm open to discussion. Perhaps we could put
them back in along 
with cautions in the manual.

Please send me a description of how you would use the
controls, i.e. 
the qualitative effects you have in mind or specific
decay values 
you've used before, etc. I'd like to evaluate how your
needs differ 
from the nominal settings already present.

Here's my reasoning for removing some of the controls:

1. Months of field testing revealed that our testers
-- despite a wide 
variety of operating styles -- barely ever changed any
of the settings 
except flatness and hold (hang) time.

2. Some combinations of settings can end up being very
confusing, 
except for the advanced and/or experimentally inclined
operator who can
recognize the side effects. This has been endlessly
played out on some 
of our competitors' rigs. I had sought to avoid such
difficulties once 
it became clear that there was such a small range in
use by our 
testers.

3. Some settings can compromise the performance not
just of AGC, but 
that of other functions, as well (e.g., DSP noise
blanking and AGC 
pulse detection/removal).

73,
Wayne
N6KR


--- wayne burdick <n6kr at elecraft.com> wrote:

> Don Rasmussen wrote:
> 
> > I don't know about anyone else, but I bought K3
> based on being able to 
> > adjust these (5) things.
> 
> Don,
> 
> It was my decision to remove them, for the reasons
> given below. It's 
> trivial to add them back in, but debatable as to
> whether it's a good 
> idea. I'm open to discussion. Perhaps we could put
> them back in along 
> with cautions in the manual.
> 
> Please send me a description of how you would use
> the controls, i.e. 
> the qualitative effects you have in mind or specific
> decay values 
> you've used before, etc. I'd like to evaluate how
> your needs differ 
> from the nominal settings already present.
> 
> Here's my reasoning for removing some of the
> controls:
> 
> 1. Months of field testing revealed that our testers
> -- despite a wide 
> variety of operating styles -- barely ever changed
> any of the settings 
> except flatness and hold (hang) time.
> 
> 2. Some combinations of settings can end up being
> very confusing, 
> except for the advanced and/or experimentally
> inclined operator who can 
> recognize the side effects. This has been endlessly
> played out on some 
> of our competitors' rigs. I had sought to avoid such
> difficulties once 
> it became clear that there was such a small range in
> use by our 
> testers.
> 
> 3. Some settings can compromise the performance not
> just of AGC, but 
> that of other functions, as well (e.g., DSP noise
> blanking and AGC 
> pulse detection/removal).
> 
> 73,
> Wayne
> N6KR
> 
> ---
> 
> http://www.elecraft.com
> 
>