Re: [Elecraft] RX Mush, why the fuss?

Guy K2AV and Dave AB7E! Your comments are incredibly helpful. I and many others would be very grateful if you would post all your Config setting related to coping with RX mush. 73, Dick WC1M 73, Dick WC1M > On Mar 3, 2017, at 1:59 PM, David Gilbert wrote: > > > I

Re: [Elecraft] RX Mush, why the fuss?

This has been an interesting discussion. We've certainly passed the posting overload limit on it though, so lets wind it down in the next hour to let others recuperate from email overload ;-) 73, Eric List mooderator.. /elecraft.com/ On 3/3/2017 10:59 AM, David Gilbert wrote: I agree with

Re: [Elecraft] RX Mush, why the fuss?

I agree with your comments. Thanks for the clarifications! And I did indeed forget to mention the attack/decay speed influences. I even posted comments here about that myself back shortly after I bought my K3 ... that the time rate of change in gain is itself a non-linearity. I think my

Re: [Elecraft] RX Mush, why the fuss?

There is some conflation of two quite different concepts going on here. The first thing you need to know about an AGC response graph is the speed that the incoming signal was varied to produce the curve. In many cases, the input signal was steady state from a signal generator, set to a list of

Re: [Elecraft] RX Mush, why the fuss?

I've had my K3 since 2008 or so, and over the years I've seen people describe different forms of "mush". One set of comments indeed involved complaints about the hard limit at the upper end that has nothing to do with AGC. It is, as you say, simply a hard limit ... pretty much a clipper to

[Elecraft] RX Mush, why the fuss?

I tend to use the CWT display a lot, and then the S-meter doesn't show 20 dB over S9. Actively using RF gain, ATT, PRE, as one should, makes the S-meter even less interesting. Eyes tend to spend a lot of time on the P3 display when available. Spectrum peaks don't show how close we are to the

Re: [Elecraft] RX Mush, why the fuss?

One problem here is that a lot of the discussion has been in analog terms. We have to remember that in the K3, the digital AGC controlled by the AGC parms is just that, a digital algorithm. What it does has nothing to do with diodes. It can do anything weird and completely non analog resembling,

Re: [Elecraft] RX Mush, why the fuss?

Oh no! I fear this is going to get bogged down in definitions. From Wikipedia: "Limiting can refer to non-linear clipping, in which a signal is passed through normally but 'sheared off' when it would normally exceed a certain threshold. It can also refer to a type of variable-gain audio level

Re: [Elecraft] RX Mush, why the fuss?

The AGC will not cause "hard limiting" - in other words, it should maintain linearity. Even though the strongest signal in the passband will control how much AGC is applied, weaker signals in the passband should sound proportionally weaker. Now that you mention hard limiting, there is a

Re: [Elecraft] RX Mush, why the fuss?

Hi, Where in Smith's article does it say that AGC with the slope set for 15 acts as a hard limiter? There is a huge difference between AGC action (which is simply a reduction in gain with linearity retained) and hard limiting. I have read the article and agree that his measurements are very

Re: [Elecraft] RX Mush, why the fuss?

It isn't so much that 'the strongest signal in the passband determines the gain of the receiver', it's that once that strong signal sends the receiver into AGC, additional signals in the passband do not increase the audio output power when the Slope is set at or near its extreme. This is a form

Re: [Elecraft] RX Mush, why the fuss?

On Wed,3/1/2017 10:29 PM, David Gilbert wrote: I recently purchased the new synths for my K3 and supposedly they help significantly on that score, but I haven't had the opportunity to install them yet. Don't put it off -- it's an easy 30 minute job. 73, Jim K9YC

Re: [Elecraft] RX Mush, why the fuss?

That isn't actually true. Threshold and slope combine to form a point of non-linearity that can cause all sorts of in-band mixing products when multiple signals exist at roughly the same levels. I and others have experienced that first hand in the past. I can running stations in a

Re: [Elecraft] RX Mush, why the fuss?

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

Re: [Elecraft] RX Mush, why the fuss?

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

Re: [Elecraft] RX Mush, why the fuss?

I too have come to that same surmise, Wes, and I hope whoever explains it [someone always does] does so on the reflector so I can benefit too. One of my K3's two AGC systems is highly configurable. I finally found a threshold and fairly flat slope that, for my compromised hearing works very

[Elecraft] RX Mush, why the fuss?

I must confess to some bewilderment about the seemingly endless discussion about the adjustment, or mis-adjustment, of AGC slope, threshold or "RF" gain. Claims are made that one's favorite settings cause signals within the passband to retain their relative amplitudes thus allowing the