Re: [Elecraft] K2 AGC, Seems a bit soft
I completely agree about the K2's great sounding AGC. The fact that there *is* some slope to the AGC to still allow the perception of various signal levels while still maintaining control, is a testament to the radio's excellent dynamic range. IMHO, it actually reduces listening fatigue by not excessively raising the noise floor for weak signals. 73, Dale WA8SRA Darwin, Keith wrote: Yes, Paul the K2's AGC is definitely "soft". Soft in that it has some slope to it with quiet signals sounding quieter than loud. And I love it that way. In fact that is one of a handful of factors that make the K2 such a sweet sounding radio and such a pleasure to listen to. I've had rigs (good rigs) with hard AGCs and they leave me feeling assaulted after a whle under the headphones. Obviously, this is only my opinion, and YMHV (your mileage has varied) - but in my book the K2's AGC is top notch. 73! - Keith N1AS - - K2 5411.ssb.100 - -Original Message- While some folks like a slightly soft AGC in the receiver, I'm one of those folks that finds that soft signals received softer than loud signals (especially SSB) is tiring. I prefer a very stiff and level AGC. Mind you, this has nothing to do with the fast/slow delay rates or anything along those lines. -Paul Pollock KD7BWB ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] K2 AGC, Seems a bit soft
Yes, Paul the K2's AGC is definitely "soft". Soft in that it has some slope to it with quiet signals sounding quieter than loud. And I love it that way. In fact that is one of a handful of factors that make the K2 such a sweet sounding radio and such a pleasure to listen to. I've had rigs (good rigs) with hard AGCs and they leave me feeling assaulted after a whle under the headphones. Obviously, this is only my opinion, and YMHV (your mileage has varied) - but in my book the K2's AGC is top notch. 73! - Keith N1AS - - K2 5411.ssb.100 - -Original Message- While some folks like a slightly soft AGC in the receiver, I'm one of those folks that finds that soft signals received softer than loud signals (especially SSB) is tiring. I prefer a very stiff and level AGC. Mind you, this has nothing to do with the fast/slow delay rates or anything along those lines. -Paul Pollock KD7BWB ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] K2 AGC, Seems a bit soft
Paul, You may find some information in the archives that could possibly help your situation. Jack Smith K8ZOA has documented a good amount of info on the AGC operation on his website and Dave White VE6DRW has created a mod to give more control over the various AGC characteristics. Look for their posts to the reflector in the February and March 2007 timeframe. It is quite likely that neither of those sources will produce the 'strong AGC' that you seem to desire (most of us like the softer K2 AGC), but may be worthwhile for study as a prelude to your re-design of the K2 AGC. On the lack of ability to get the AGC Threshold up to 3.8 volts - do not be overly concerned about that - the maximum voltage is related to the 8 volt regulator actual voltage. Furthermore, if your AGC is active even with no signal, you should *lower* the AGC Threshold voltage. I know it sounds counter-intuitive, but results from the point where the voltage is measured. Warning, if your AGC Threshold voltage is too low, your S-meter settings will become a bit 'squirrelly', and for that reason I recommend that you do not reduce the AGC Threshold below 3.65 volts in any case. Changes from the 'standard' designs and settings may be made, that is part of the K2 'fun' - try it and see what happens, you can always set it back to the 'standard'. 73, Don W3FPR Paul Pollock wrote: I am enjoying my recently completed K2-6148 very much, but I had a couple of questions and thought others might have some constructive thoughts. While some folks like a slightly soft AGC in the receiver, I'm one of those folks that finds that soft signals received softer than loud signals (especially SSB) is tiring. I prefer a very stiff and level AGC. Mind you, this has nothing to do with the fast/slow delay rates or anything along those lines. 1). My K2 exhibits good AGC performance and I believe it works as designed, but it is a soft AGC. Are there any ideas on modifications to the AGC IC (LM833) that might stiffen the AGC performance? 2). I'm another of those folks where my AGC threshold voltage will not go above 3.7x volts. It is my feeling that a threshold set so that the AGC actually releases at the noise level is better than a setting where the AGC is ON at all levels. On my K2 the AGC never releases at any level. Any thoughts on getting the AGC to release correctly? ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K2 AGC, Seems a bit soft
I am enjoying my recently completed K2-6148 very much, but I had a couple of questions and thought others might have some constructive thoughts. While some folks like a slightly soft AGC in the receiver, I'm one of those folks that finds that soft signals received softer than loud signals (especially SSB) is tiring. I prefer a very stiff and level AGC. Mind you, this has nothing to do with the fast/slow delay rates or anything along those lines. 1). My K2 exhibits good AGC performance and I believe it works as designed, but it is a soft AGC. Are there any ideas on modifications to the AGC IC (LM833) that might stiffen the AGC performance? 2). I'm another of those folks where my AGC threshold voltage will not go above 3.7x volts. It is my feeling that a threshold set so that the AGC actually releases at the noise level is better than a setting where the AGC is ON at all levels. On my K2 the AGC never releases at any level. Any thoughts on getting the AGC to release correctly? Thanks in advance! -Paul Pollock KD7BWB ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
