[Elecraft] K3 Receiver mush

[W0MU Mike Fatchett]

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-bounces at 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.
>>>>