Don W3FPR wrote: >If any of you do not know what we are referring to, go to my website >www.w3fpr.com and in the left column, click on the "Noisy K3" article. >It will give you guidelines for adjusting the K3/K3S AGC parameters to >better suit your operating preferences. The default settings are OK, >but are not optimum for every operating style and noise environment.
That last sentence is all too true! For DXers and contesters, maybe it is time to re-post the following information from 5-6 years ago. *************** Many DXers and contesters are still using the factory default AGC settings, completely unaware that their K3/K3S *could* perform so much better. 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, while many competing rigs have a threshold of S7 or even higher. This very low AGC threshold is what often allows the AGC to be activated by band noise. The 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 greatly reduce the differences in the real-life strengths of incoming signals. These are differences that DXers and contesters *want* and *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, May 2012). After the release of FW v4.51, users began to experiment. The following is a consensus within the [K3-contesting] Yahoo group about the most important settings for DXing and contesting [2]. * AGC THR: increase to at least 8 (from default = 5) and preferably to 12. Then take some time to become accustomed to the wider range of audio levels. Repeat: you may need to give the increased AGC THReshold setting an extended trial. What you became accustomed to with the factory setting of THR=5 was an artificially restricted range of audio signal levels, so a higher THR setting will initially sound quite 'aggressive' - but it is also much closer to real life. * 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. Note: the effects of SLP are partly determined by the THR setting that you already made (at higher THR levels, SLP has less effect). So always experiment with THR first, and then adjust SLP as the second step [1]. * 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 changes 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 even *possible*. It is now 6 years since the v4.51 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, along with any advice about how to configure the related AGC settings. Also the factory AGC defaults remain exactly as they were, optimized for 'comfortable listening' but far from optimum for DXing and contesting. One has to wonder how many DX QSOs have been lost as a result... [1] http://www.ke7x.com/home/miscellaneous-k3-information [2] The [K3-contesting] group served its purpose and then closed down. ************ 73 from Ian GM3SEK ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
