Thanks.
My threshhold was at 8 I have moved it up to 12. Slope was zero but I
change it all the time hoping for a miracle! HI!
I am going to have to borrow another rig when I get back and see if I
see the same things on another brand.
W0MU
On 2/22/2017 1:42 AM, Ian White wrote:
Re-posting from April 2016, and earlier:
73 from Ian GM3SEK
***************
The factory default AGC THReshold for the K3 and K3S is very, very low.
Measurements by KE7X [1] have shown that the default setting of THR=5
corresponds to an AGC onset at less than S3, whereas competing rigs have
a threshold of S7 or even higher. This very low AGC threshold is what
allows the AGC to be activated by band noise.
Elecraft's factory defaults of THR=5 and SLP=12 compress all signals
above the AGC threshold into a very narrow range of audio output levels
[see the measurements by KE7X]. This makes for comfortable
broadcast-style listening - but there is price to be paid. The default
settings tend to hide the real-life differences in the strengths of
incoming signals - important differences that DXers and contesters
*need* to hear, in order to pick individual signals out of a pileup.
Following complaints from DXers, DXpeditioners and contesters about this
so-called "pileup mush", and following further series of measurements by
KE7X, Elecraft eventually did increase the available range of AGC
THReshold settings (the v4.51 firmware upgrade).
Following the release of FW v4.51, the consensus within the
[K3-contesting] Yahoo group about the most important settings for DXing
and contesting has been as follows.
* AGC THR: increase to at least 8 (from default = 5) and preferably to
12, and then take some time to become re-accustomed to the increased
range of audio levels [2]. (Some users recommend as high as 14, if your
ears can handle it.)
* AGC SLP: decrease to 8 or even less (from default = 12). Lower SLP
settings allow stronger signals to sound somewhat louder, and thus more
realistic, but the range of variation will be partly determined by the
THR setting already made; so always experiment with THR first, and with
SLP afterwards.
* AGC DCY = SOFT (not default=NOR). The User Manual claims that "The
SOFT setting can reduce IMD caused by traditional AGC, and is especially
useful in 'pileup' conditions, in some cases making it unnecessary to
turn AGC off."
The settings recommended above have essentially solved the problem of
"pileup mush" for those who have tried them... but regrettably, Elecraft
has done almost nothing to make DXers and contesters aware that such
changes are possible.
More than 3 years after the firmware release notes boasted that v4.51
"greatly improves signal clarity in pile-ups and other high-noise or
dense-signal situations, especially with threshold set to 12 or higher",
that information is *still* missing from the User Manual. There is also
no information on how to create different 'profiles' of AGC settings for
different types of users.
Meanwhile, Elecraft's factory AGC defaults remain exactly as they were,
still optimized apparently for comfortable 'listening', while many DXers
and contesters remain unaware that their K3/K3S could actually be *so*
much better.
[1] http://www.ke7x.com/home/miscellaneous-k3-information
[2] It is important to give any increased AGC THReshold setting an
extended trial. To anyone accustomed to an artificially restricted range
of audio signal levels, a higher setting will initially sound quite
'aggressive' - even though the new setting is much closer to real life.
************
-----Original Message-----
From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of
W0MU Mike Fatchett
Sent: 22 February 2017 00:39
To: Elecraft Reflector
Subject: Re: [Elecraft] K3 Receiver mush
I can run with 400 or 250hz filters.
I have tried it with AGC fast, slow off etc.
I just think this is something that most people just never see. This
was
a major point of discussion a while back. I guess it is just the way
the radio is. I will have to try another rig to see if I notice the
same effects.
In a pileup there is no offending station they are all calling me.
I was just curious if other contesters or DXpeditioners settings might
be and if they are still seeing this issue.
W0MU
On 2/21/2017 8:48 AM, Don Wilhelm wrote:
Mike,
Think about it - if there are multiple signals in the passband, the
AGC will respond to the strongest, there is just no way around that
fact.
If the signals can be separated by the DSP, and one is really strong,
that strong station may be activating the Hardware AGC. The only
solution for the latter is a more narrow roofing filter - put the
offending strong signal out of the passband of the roofing filter and
use shift to get your sidetone for the desired signal back in order.
That may be too much "fiddling" for a run station in a contest, but
it
is a viable way to operate when trying to copy a weak station working
close to a strong station.
73,
Don W3FPR
On 2/21/2017 9:25 AM, W0MU Mike Fatchett wrote:
We noticed again during the contest hat when 3 or 4 stations called,
all
those signals would be flattened to the same level. Once you got to
where one or two stations were calling the signal level would pop up
substantially.
I have played endlessly with slope and threshold with little effect.
My K3 has the new syn boards as well and filters from 2.8 to 2.5.
Latest firmware etc.
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